The Historical and Ecological Significance of Summit Valley and Its Surroundings

Summit Valley: A Historical Overview

Summit Valley is a region rich in history and natural beauty in Southern California. Nestled between the Mojave Desert and the Southern California Mountains, it lies east of the Cajon Pass. Hesperia borders it to the north and the San Bernardino National Forest to the south. This valley, traversed by the West Fork of the Mojave River, holds significant historical and ecological importance.

Key Historical Figures and Events

1776: Fr. Francisco Garcés

Francisco Garcés, a Spanish Franciscan missionary and explorer, traveled through Summit Valley in 1776 as part of his extensive travels across the American Southwest. Garcés played a crucial role in establishing early routes and missions in the region, and his detailed diaries provide valuable insights into the landscape and indigenous peoples.

1826: Jedediah Smith

Looking west across the valley

Jedediah Smith, a renowned American frontiersman, trapper, and explorer, led an expedition through Summit Valley in 1826. This marked one of the earliest American explorations of the region, significantly contributing to the mapping and understanding of the Western United States.

1840: Chaguanoso Raid

Raiders would run the horses to death if they had to–the stakes were high. (BLM photo colorized)

The Chaguanoso raid was the largest stock theft in California’s history. On May 14, 1840, Juan Perez, the administrator of Mission San Gabriel, reported the theft of mares by Chaguanoso raiders. Tiburcio Tapia, a prominent Californian businessman and alcalde of Los Angeles, directed the pursuit of the robbers who crossed the Mojave Desert. Despite the efforts of men like Ygnacio Palomares and José Antonio Carrillo, the raiders largely escaped.

A possible site of Campo de la Puente (Camp on the bridge)

Early 1840s: Michael White (Miguel Blanco)

In the early 1840s, Michael White (Miguel Blanco) confronted horse thieves led by Chief Coyote in Crowder Canyon. White’s successful defense of his cattle, culminating in the killing of Chief Coyote, marked a significant moment in the region’s history and highlighted the persistent threat of banditry.

Settlement and Development

1866: Summit Valley Massacre

Massacre site

On March 25, 1866, Edwin Parrish, Nephi Bemis, and Pratt Whiteside, young cowboys employed at Las Flores Ranch, were ambushed and killed by Piute Indians near Las Flores Ranch. This violent episode highlighted the ongoing tensions between settlers and native populations.

Late 1800s: Las Flores Ranch

In the late 1800s, cattle driven from Arizona were pastured on Summit Valley’s green grass and running water and fattened before being sent to market in San Bernardino. Despite the challenges from wildlife and hostile natives, the ranch became central to the regional economy.

1884-1885: Railroad Construction

The construction of the Southern California Railroad in 1884-1885, following the old Spanish Trail route, was a significant development. Summit, located about six miles west of the Bircham Ranch, became a crucial station for shipping supplies. Despite unsuccessful oil explorations, the area continued to develop.

Early 1900s: Agricultural Growth

Looking northeast from the mouth of Cedar Springs Canyon

Summit Valley’s fertile lands and plentiful water made it an attractive location for cattle ranching. Early settlers capitalized on these resources, establishing large ranches that became central to the valley’s economy. Over time, the introduction of railroads and improved transportation infrastructure facilitated the growth of agriculture and livestock trade, further cementing the valley’s role as a key agricultural hub.

1924: Modern Infrastructure

Looking east into Horsethief Canyon on SR 138 – November 2015

By the early 20th century, the region had developed a network of roads and railroads, with State Route 138 emerging as a critical transportation corridor. This infrastructure supported the valley’s continued growth and integration into the broader Southern California economy while preserving its historical legacy and natural beauty.

Ecological and Recreational Importance

Biodiversity and Conservation

Summit Valley has diverse habitats, from montane forests and riparian zones to grasslands and desert ecosystems. These habitats support a variety of wildlife, including many species of birds, mammals, and plants. Conservation efforts in the valley focus on protecting these natural resources, managing invasive species, and ensuring the region’s ecological health.

Silverwood Lake and Recreational Activities

Cedar Springs Dam

The creation of Silverwood Lake as part of the California State Water Project has significantly enhanced the recreational opportunities in Summit Valley. The lake offers boating, fishing, hiking, and camping activities, attracting regional visitors. The Pacific Crest Trail, which passes through the valley, provides additional opportunities for outdoor enthusiasts to explore the area’s natural beauty.

Cedar Springs, CA

Downtown Cedar Springs, CA.

Cedar Springs was a small community in the San Bernardino Mountains, submerged by the creation of Silverwood Lake in 1971. Before the lake’s construction, Cedar Springs was known for its natural beauty, with lush cedar forests and clear springs that attracted visitors and residents alike. While the community was lost, the lake’s creation transformed the area into a major recreational destination.


Summit Valley’s rich history, from early exploration by figures like Francisco Garcés and Jedediah Smith to significant events like the Chaguanoso raid and Summit Valley massacre, paints a vivid picture of a region that has played a crucial role in Southern California’s story. From the challenges faced by early settlers to its modern-day significance as a recreational and ecological haven, Summit Valley remains a testament to the dynamic interplay between human activity and the natural world.

Horse Stealing in the American West: A Complex Saga of Survival, Conflict, and Lawlessness

In the mid-19th century, the American West was a land of vast open spaces, sparse settlements, and a constant struggle for survival. Among the various challenges faced by settlers, Native Americans, and other inhabitants of the region, horse stealing emerged as a significant and often dangerous activity. This essay explores the multifaceted nature of horse stealing, its impact on different communities, and the notable figures involved in these activities, focusing on the Mojave Desert and surrounding areas.

Historical Context and Importance of Horses

Horses were introduced to North America by Spanish explorers in the 16th century and quickly became integral to the way of life for many Native American tribes. By the 19th century, horses were indispensable for transportation, labor, hunting, and warfare. For settlers and ranchers, horses were crucial assets, representing significant economic value and practical utility.

The California Gold Rush of the late 1840s brought settlers to the region, intensifying resource competition and escalating conflicts between different groups. Horses’ value made them prime targets for theft, and horse stealing became a widespread problem, contributing to the lawlessness and violence that characterized much of the frontier.

Techniques and Tactics of Horse Stealing

Horse stealing requires a combination of skill, knowledge, and audacity. Thieves often operated in bands, using well-planned tactics to carry out their raids. These tactics included:

  1. Night Raids: Most horse thefts occurred at night when thieves took advantage of the darkness to avoid detection and increase their chances of a successful escape.
  2. Remote Trails: Thieves used remote trails and difficult terrain to evade pursuers. Their knowledge of the landscape was a significant advantage, allowing them to move swiftly and remain hidden.
  3. Speed and Surprise: The element of surprise was crucial. Thieves would strike quickly, gather as many horses as possible, and leave before the victims could organize a response.
  4. Dispersal and Fencing: Stolen horses were often dispersed among various locations or quickly sold to fences, making it difficult for the rightful owners to recover them.

Notable Figures in Horse Stealing

Several prominent figures became infamous for their involvement in horse stealing. Their stories highlight the complexities and contradictions of frontier life.

Walkara: The Ute Leader

Walkara, also known as Chief Walker, was a Ute leader born around 1808. He became one of the most feared and respected figures in the Great Basin and Mojave Desert regions due to his prowess in horse stealing. Leading numerous raids from Utah into California, Walkara amassed thousands of horses. His knowledge of the terrain and guerrilla tactics made him a formidable opponent. Despite his reputation as a horse thief, Walkara was also a shrewd leader and negotiator, embodying the dual roles of protector and predator standard among Native American leaders of the time.

Jim Beckwourth: The Adventurous Frontiersman

James P. Beckwourth, a mixed-race mountain man, fur trader, and explorer, was born into slavery in 1798 and gained his freedom to become one of the most colorful figures of the American frontier. While primarily known for his role as a trader and guide, Beckwourth’s interactions with various Native American tribes, including the Crow, often placed him amid horse raiding activities. His involvement in horse stealing adds another layer to his multifaceted legacy, reflecting the blurred lines between legitimate trade and outlaw activities on the frontier.

Peg-leg Smith: The Notorious Thief

Thomas L. “Peg-leg” Smith, born in 1801, was notorious for horse-stealing raids across the Southwest. Known for his wooden leg, Smith conducted large-scale raids on Mexican ranchos, stealing hundreds of horses and driving them north to American markets. His daring exploits and cunning escapes made him a legendary figure in Western folklore, contributing to the mythos of the Wild West. Smith’s activities disrupted the economies of the regions he targeted and highlighted the challenges of maintaining law and order in the frontier.

The Case of Indian Joaquin

Indian Joaquin, also known as Joaquin Valenzuela, was another significant figure in horse stealing. His band of outlaws, including the Mojave Desert, was active in California and was known for their bold raids. In 1845, Governor Pio Pico sent Benjamin Davis Wilson to lead an expedition against these horse thieves. Wilson’s mission culminated in a confrontation where he shot and killed Indian Joaquin. This event marked a significant moment in the struggle between settlers and Native American bands, illustrating the harsh measures taken to protect property and assert dominance in the region.

Responses to Horse Stealing

The persistent threat of horse stealing led to various responses from both military and civilian authorities:

  1. Military Patrols: Increased military presence and patrols aimed to protect settlements and ranchos from raids. Forts and outposts were established strategically to serve as bases for these operations.
  2. Vigilance Committees: Settlers often formed vigilance committees to protect their property and pursue horse thieves. These groups operated outside formal legal structures, using extrajudicial methods to capture and punish suspected thieves.
  3. Negotiations and Treaties: In some cases, attempts were made to negotiate with raiding groups to establish peace and trade agreements. However, these efforts were often temporary and depended on the shifting dynamics of power and resources.

Impact and Legacy

The impact of horse stealing in the American West was profound, influencing economic stability, social dynamics, and cultural interactions. The legacy of horse stealing includes:

  1. Economic Disruption: The theft of horses had significant economic implications, disrupting transportation, labor, and trade. For many settlers, losing horses meant a critical setback in establishing livelihoods in the harsh frontier environment.
  2. Cultural Tensions: Horse stealing exacerbated tensions between different cultural groups, including Native Americans, Mexican landowners, and American settlers. These tensions often led to violent confrontations and shaped the broader patterns of conflict in the region.
  3. Folklore and Mythology: The exploits of horse thieves and the responses to their activities became part of the folklore of the American West. Stories of daring raids, cunning escapes, and brutal reprisals contributed to the mythos of the Wild West, reflecting the complexities of frontier life.
  4. Law and Order: The persistent threat of horse stealing highlighted the challenges of maintaining law and order in the rapidly expanding frontier. Responses to this threat, including military actions and vigilance committees, underscored the often violent efforts to establish security and protect property.


Horse stealing in the American West, particularly in the Mojave Desert and surrounding regions, was a complex phenomenon that significantly shaped the frontier’s history and culture. The activities of Walkara, Jim Beckwourth, Peg-leg Smith, and Indian Joaquin illustrate the multifaceted nature of horse stealing, reflecting broader themes of survival, resistance, and adaptation in a rapidly changing landscape.

The responses to horse stealing, from military patrols to vigilance committees, highlight the ongoing struggle to establish order and protect property in a region marked by turmoil and conflict. The legacy of horse stealing, with its economic, social, and cultural impacts, continues to be a fascinating and integral part of the history of the American West. Through the stories of these notorious figures and the broader patterns of conflict and adaptation, we gain valuable insights into the dynamic and often chaotic nature of 19th-century frontier life.

Historic Fort Mojave: A Pillar of Frontier Defense


Historic Fort Mojave, located along the Colorado River in Arizona, is a landmark of significant historical and cultural importance. Established in 1859 by the United States Army, the fort served multiple roles, from protecting settlers and travelers to acting as a military stronghold during the turbulent times of the Indian Wars and the American Civil War. The fort’s history reflects the broader narrative of westward expansion, conflict, and cultural change in 19th-century America.

Establishment and Strategic Importance

Fort Mojave was strategically situated on the east bank of the Colorado River, near present-day Fort Mojave in Mohave County, Arizona. Its creation was primarily driven by the need to safeguard settlers and travelers navigating the perilous Mojave Road, a crucial route connecting the east and west coasts. The fort’s location was pivotal, offering a military advantage in a region where control over territory was contested by various Native American tribes, particularly the Mojave tribe.

The fort’s initial garrison faced daunting challenges, including harsh desert conditions, extreme temperatures, and limited water resources. Despite these adversities, Fort Mojave emerged as a critical outpost in the United States’ efforts to secure its expanding frontiers. During the Indian Wars, the fort played a key role in military operations aimed at pacifying and relocating Native American tribes, a mission fraught with conflict and complexity.

Role During the Civil War

During the American Civil War, Fort Mojave’s strategic value increased. It served as a vital supply depot and base for Union forces operating in the Southwest. The fort’s presence ensured Union control over a vast and remote region, deterring Confederate incursions and maintaining supply lines crucial for the war effort. This period marked the fort’s peak in military significance, as it became a hub of logistical and operational activity in a largely unsettled frontier.

Garrison Life and Economic Impact

Life at Fort Mojave for soldiers and their families was a mix of military routine and adaptation to the harsh desert environment. Daily activities included drills, patrols, and maintaining the fort’s infrastructure. The soldiers’ resilience in extreme conditions is a testament to their determination and discipline. The fort also acted as a catalyst for local economic development. The influx of soldiers and associated personnel brought economic activity to the area, fostering the growth of nearby settlements and creating a foundation for future community development.

Decline and Post-Military Use

As the Indian Wars subsided and the American frontier became more settled, Fort Mojave’s military importance waned. By 1890, the fort was officially abandoned by the military. However, its legacy continued as the site found new life in various civilian roles. Notably, it was repurposed as a reservation school for Native American children, symbolizing a shift from conflict to education and cultural integration.

Establishing the Fort Mojave Indian Reservation further ensured the preservation of the site’s historical and cultural significance. The reservation, which spans Arizona, Nevada, and California, has become a vibrant community engaged in agriculture, gaming, and tourism. Efforts to preserve and interpret the history of Fort Mojave include historical markers and exhibits, which provide educational opportunities for visitors and honor the fort’s complex past.

Cultural and Historical Significance

Fort Mojave is a significant cultural heritage site for the Mojave tribe and other Native American communities. It embodies a period of dramatic transition, reflecting the broader themes of westward expansion, military strategy, and cultural interaction in American history. The fort’s preservation efforts underscore the importance of remembering and understanding this chapter of the American frontier.


Historic Fort Mojave is more than a relic of military history; it is a symbol of the enduring legacy of the American West. From its establishment as a frontier defense outpost to its role in the lives of Native American communities, Fort Mojave offers a window into the complex and often contentious history of the 19th-century American frontier. Its story is a testament to resilience, adaptation, and the enduring significance of cultural heritage in shaping our understanding of the past.

Grasshopper Mouse

The grasshopper mouse, belonging to the genus Onychomys, is a fascinating creature known for its unique behaviors and adaptations. Here’s a detailed overview of its natural history:

Physical Description

  • Size: Small rodents, typically around 4 to 5 inches in body length, with an additional 1 to 2 inches of tail.
  • Appearance: They have a robust body, short tails, and large ears. Their fur is generally grayish-brown on the back and white on the belly.


  • Geographic Range: Found in North America, particularly in the arid and semi-arid regions of the western United States and Mexico.
  • Preferred Environment: Grasshopper mice inhabit deserts, scrublands, and prairies. They are well-adapted to dry environments and can be found in areas with sparse vegetation.


  • Nocturnal Lifestyle: These mice are primarily nocturnal, coming out to hunt and forage at night.
  • Territoriality: Grasshopper mice are highly territorial and aggressive. They establish and defend territories vigorously.


  • Carnivorous Diet: Unlike many other rodents, grasshopper mice are primarily carnivorous. They feed on insects, other small invertebrates, and even small vertebrates.
  • Specialization: They are named for their tendency to prey on grasshoppers, but their diet can also include beetles, scorpions, spiders, and even other mice.
  • Hunting: Known for their hunting prowess, they are sometimes called “scorpion mice” due to their ability to hunt and consume scorpions, showing resistance to the venom.


  • Unique Calls: Grasshopper mice are known for their high-pitched, wolf-like howls, which they use to communicate with each other, especially to mark territory.


  • Breeding Season: Typically breed from spring through late summer.
  • Litter Size: Females give birth to 2 to 6 young after a gestation period of about 30 days.
  • Parental Care: The young are weaned after a few weeks and reach maturity at around 2 to 3 months.


  • Water Conservation: Adapted to arid environments, grasshopper mice obtain most of their water from the food they eat and have efficient kidneys to conserve water.
  • Venom Resistance: They have developed a resistance to the venom of scorpions, allowing them to prey on these arachnids without harm.

Ecological Role

  • Predator Control: By preying on insects and other small animals, grasshopper mice help control the populations of these species in their habitats.
  • Indicator Species: Their presence and health can be indicators of the ecological balance in their environment.

The grasshopper mouse’s unique dietary habits, vocalizations, and behaviors make it a remarkable example of adaptation to harsh environments, playing a crucial role in the ecosystems they inhabit.

Comparative Geomorphology

Here’s a comparison between the geomorphology of the Funeral Mountains – Greenwater Valley subsection and the second geomorphological description:

Funeral Mountains and Greenwater Valley

  • Landforms: Steep to very steep mountains and valleys, with very gently to moderately sloping alluvial fans, nearly level basin floors, and dry lake beds.
  • Orientation: Mountains align north-south or north-northwest.
  • Elevation Range: About 1,000 feet to 6,703 feet on Pyramid Peak, with many peaks over 5,000 feet.
  • Geomorphic Processes: Mass wasting, fluvial erosion and deposition, and eolian deflation and deposition.


Geomorphology is the scientific study of landforms and the processes that shape them, including their origin, evolution, and spatial distribution.

Lucerne and Johnson Valleys

  • Landforms: Steep mountains, moderately steep hills, gently to moderately sloping pediments and alluvial fans, nearly level basin floors, and dry lake beds. Presence of “badlands” on eroded Miocene nonmarine sedimentary rocks.
  • Orientation: The hills’ general orientation is less straightforward than the major faults, which trend northwest.
  • Elevation Range: About 1,600 feet up to 4,873 feet in the Granite Mountains, 5,525 feet in the West Ord Mountains, 6,309 feet in the East Ord Mountains, and 5,878 feet in the Rodman Mountains.
  • Dry Lake Beds: Includes Lucerne, Soggy, Melville, Galway, Emerson, and Deadman Lake.
  • Geomorphic Processes: Mass wasting, fluvial erosion and deposition, and eolian deflation and deposition.
Greenwater Valley, Death Valley National Park


  • Landforms: Both regions feature steep mountains and valleys, alluvial fans, basin floors, and dry lake beds. However, the second description includes pediments and mentions “badlands,” which are not noted in the Funeral Mountains – Greenwater Valley description.
  • Orientation: The Funeral Mountains – Greenwater Valley mountains align north-south or north-northwest, while the hills in the second description have a less clear orientation than the major northwest-trending faults.
  • Elevation Range: The Funeral Mountains – Greenwater Valley has a broader elevation range, reaching higher peaks (up to 6,703 feet), whereas the second area reaches 6,309 feet in the East Ord Mountains.
  • Dry Lake Beds: The second description specifies several large dry lake beds by name, which are not mentioned in the Funeral Mountains – Greenwater Valley description.
  • Geomorphic Processes: Both regions experience similar geomorphic processes, including mass wasting, fluvial erosion and deposition, and eolian deflation and deposition.

In summary, while both regions share common geomorphic features and processes, they differ in specific landform characteristics, elevation ranges, and the presence of features such as “badlands” and named dry lake beds.

Geologic Diversity

When someone mentions they are a geologist, it’s easy to assume that all geologists do the same thing. However, geology is a diverse and multifaceted field, encompassing a wide range of specialties. Each geologist may focus on different aspects of the Earth’s structure, materials, processes, and history. Here’s a more detailed look at the various types of geology and the distinct roles that geologists might have:

Types of Geology

  1. Structural Geology: Geologists in this field study the architecture and processes responsible for the deformation of the Earth’s crust. They analyze faults, folds, and rock formations to understand tectonic movements and stress patterns.
  2. Petrology: Petrologists examine the origin, composition, and structure of rocks. They specialize in:
    • Igneous Petrology: Focuses on rocks formed from magma or lava.
    • Sedimentary Petrology: Studies rocks formed by the accumulation of sediments.
    • Metamorphic Petrology: Investigates rocks transformed by heat and pressure.
  3. Mineralogy: Mineralogists study minerals, including their structure, properties, classification, and distribution. They identify and analyze mineral compositions in various geological contexts.
  4. Geochemistry: Geochemists explore the chemical composition of Earth materials and the chemical processes occurring within and on the Earth’s surface. They study element cycles and mineral interactions.
  5. Geomorphology: Geomorphologists study landforms and the processes that shape them. They analyze erosion, weathering, and sediment deposition to understand landscape evolution.
  6. Sedimentology: Sedimentologists focus on sediments and sedimentary rocks, including their formation, transport, and deposition. They study sedimentary environments like rivers, lakes, and oceans.
  7. Paleontology: Paleontologists study fossils and ancient life forms to understand the history of life on Earth. They analyze fossil records to reconstruct past ecosystems and evolutionary trends.
  8. Volcanology: Volcanologists study volcanoes, volcanic processes, and volcanic rocks. They monitor volcanic activity and assess eruption risks.
  9. Seismology: Seismologists study earthquakes and the propagation of seismic waves through the Earth. They analyze seismic data to understand earthquake mechanics and predict future events.
  10. Geophysics: Geophysicists use physical methods to study the Earth’s interior and its physical properties. They specialize in:
    • Seismic Geophysics: Uses seismic waves to map the Earth’s interior.
    • Magnetic Geophysics: Studies the Earth’s magnetic field and anomalies.
    • Gravitational Geophysics: Examines variations in the Earth’s gravitational field.
  11. Hydrogeology: Hydrogeologists study groundwater, its distribution, movement, and quality. They analyze aquifers and manage water resources.
  12. Engineering Geology: Engineering geologists apply geological knowledge to construction and environmental management engineering practices. They assess ground stability and risks for infrastructure projects.
  13. Environmental Geology: Environmental geologists focus on human interaction and the geological environment. They address natural hazards and resource management to mitigate environmental impacts.
  14. Economic Geology: Economic geologists study materials for financial and industrial purposes, such as minerals, oil, and gas. They explore and develop natural resources.
  15. Planetary Geology: Planetary geologists study the geology of other celestial bodies, such as moons, planets, and asteroids. They analyze surface features and geological processes beyond Earth.

Each type of geologist brings unique expertise to their field, contributing to a comprehensive understanding of the Earth’s dynamic systems. Understanding these distinctions helps us appreciate geologists’ specialized skills and knowledge of various challenges and projects.


Geology is a diverse field with various specialties. Structural geologists study Earth’s crust deformation, while petrologists focus on rock origins and types. Mineralogists analyze minerals, and geochemists explore Earth’s chemical processes. Geomorphologists study landforms, sedimentologists examine sediments, and paleontologists investigate fossils. Volcanologists monitor volcanic activity, seismologists study earthquakes, and geophysicists use physical methods to probe Earth’s interior. Hydrogeologists focus on groundwater, engineering geologists apply geology to construction, and environmental geologists manage natural hazards. Economic geologists explore resources like minerals and oil, and planetary geologists study celestial bodies. Each specialty offers unique insights into Earth’s processes and history.

Parietal Eye

The parietal eye, also known as the third eye, is a part of the pineal gland and is found in some species of reptiles and amphibians. It is a photosensitive organ located on the top of the head and is capable of detecting light and dark. Here are some key points about the parietal eye:

  1. Location and Structure: The parietal eye is situated in the parietal area of the brain, on the top of the head, and it is visible as a small, light-sensitive spot in some reptiles and amphibians.
  2. Function: The parietal eye’s primary function is to detect changes in light intensity, helping the animal regulate its circadian rhythms and hormone production. It can also influence basking, thermoregulation, and seasonal reproduction.
  3. Presence in Species: The parietal eye is found in various species of reptiles, such as some lizards (like iguanas) and tuataras, as well as some species of amphibians and fish. It is not present in birds or mammals.
  4. Evolutionary Aspect: The parietal eye is considered an ancient feature in vertebrate evolution, reflecting an early adaptation to environmental light changes.
  5. Comparison with Pineal Gland: While the parietal eye is light-sensitive, the pineal gland in other vertebrates (including humans) receives light information indirectly through the eyes and the brain. Both structures are involved in regulating circadian rhythms and reproductive cycles.

In summary, the parietal eye is an intriguing evolutionary feature that aids certain reptiles and amphibians in detecting environmental light and regulating physiological functions.

The Parietal Eye: Nature’s Light Sensor

The parietal eye, often called the third eye, is a fascinating feature found in some reptiles and amphibians. This photosensitive organ, located on the top of the head, plays a crucial role in detecting light and dark and aids in regulating various physiological processes.

Structure and Location

The parietal eye is situated in the parietal area of the brain and is visible as a small, light-sensitive spot. Unlike the primary eyes, which detect images, it acts as a direct light sensor. This organ is found in certain lizards (including iguanas), tuataras, and some amphibians and fish. Birds and mammals, however, do not possess this feature.

Function and Role

The primary function of the parietal eye is to detect changes in light intensity, helping the animal maintain its circadian rhythms and regulate hormone production. This detection influences behaviors such as basking, thermoregulation, and seasonal reproduction. By sensing light, the parietal eye helps these animals adapt to their environment, optimizing their physiological and behavioral responses.

Evolutionary Significance

The presence of the parietal eye is an ancient adaptation, reflecting early vertebrate evolution. It showcases how animals have developed specialized organs to respond to environmental changes. While the parietal eye is a direct light sensor, other vertebrates, including humans, rely on the pineal gland for similar functions. The pineal gland receives light information indirectly through the eyes and brain, playing a key role in regulating circadian rhythms and reproductive cycles.


The parietal eye is a remarkable evolutionary feature that underscores the diversity of adaptations in the animal kingdom. By detecting light and dark, it enables reptiles and amphibians to finely tune their behaviors and physiological processes to their environments, ensuring their survival and reproductive success.


The parietal eye, or third eye, is a light-sensitive organ found in some reptiles and amphibians, situated on the top of the head. It detects changes in light intensity, aiding in regulating circadian rhythms, hormone production, and behaviors like basking and thermoregulation. Present in species such as lizards, tuataras, and some amphibians, this ancient adaptation highlights early vertebrate evolution. Unlike the parietal eye, the pineal gland in other vertebrates receives light information indirectly through the eyes and brain. This unique feature helps these animals optimize their responses to environmental changes, ensuring survival and reproductive success.

Dune Saltation

Dune saltation is a key process in the formation and movement of dunes. It involves the hopping or bouncing movement of sand grains across the surface, driven by wind. Here’s a detailed explanation:

Dune Saltation Process

  1. Initiation: Wind speeds reach a threshold where they can lift sand grains from the ground. This threshold varies depending on the size and weight of the grains, as well as the wind speed and direction.
  2. Lift-off: Sand grains are lifted into the air by the wind. The initial lift is usually caused by the impact of other grains, which creates a chain reaction.
  3. Transport: Once airborne, the grains are carried by the wind. They travel a short distance before falling back to the ground due to gravity.
  4. Impact: When the grains land, they can dislodge other grains, causing them to lift off and continue the saltation process. This impact also leads to the erosion and smoothening of the surface.
  5. Repetition: The cycle of lift-off, transport, and impact continues, causing the sand grains to move in a series of short hops or bounces.

Factors Influencing Saltation

  • Wind Speed: Higher wind speeds increase the distance and height of saltation.
  • Grain Size: Smaller grains are more easily lifted and carried by the wind, while larger grains require stronger winds.
  • Surface Conditions: Smooth surfaces allow for easier saltation, while rough surfaces can trap grains and reduce movement.
  • Moisture: Moisture in the sand can cause grains to stick together, inhibiting saltation.

Impact on Dune Formation

  • Dune Shape: Saltation contributes to the growth and movement of dunes. The continuous movement of sand grains causes dunes to migrate toward the prevailing wind.
  • Sorting of Grains: Saltation can lead to sorting grains by size, transporting finer grains further than coarser ones.
  • Erosion and Deposition: Saltation causes erosion and deposition, shaping the landscape and forming various dune structures, such as crescent-shaped barchan and linear dunes.

Understanding dune saltation is crucial for studying desert geomorphology and predicting changes in dune landscapes.

Dune saltation is the wind-driven process where sand grains are lifted, transported, and deposited in a series of hops. Wind lifts grains into the air, which then travel short distances before falling back, dislodging other grains upon impact. This cycle causes sand to move and shapes dunes. Wind speed, grain size, surface conditions, and moisture influence saltation. Higher wind speeds and smaller grains increase movement, while moisture and rough surfaces reduce it. Saltation contributes to dune formation, migration, and sorting of grains by size, playing a crucial role in desert geomorphology.

Difference between standard and narrow gauge railroads

SP Standard Gauge Engine No. 3203 and Narrow Gauge Engine No. 18 at Owenyo in 1951 –

The primary difference between standard gauge and narrow gauge railroads lies in the distance between the two rails, known as the gauge.

Standard Gauge

  1. Definition: Standard gauge is a rail gauge with a distance of 4 feet 8.5 inches (1,435 mm) between the inside edges of the rails.
  2. Prevalence: It is the most widely used rail gauge worldwide, found in approximately 60% of all railway lines.
  3. Advantages:
    • Interchangeability: Standard gauge allows for seamless interchange of rolling stock and locomotives across different regions and countries using the same gauge.
    • Stability and Speed: Standard gauge tracks provide a stable and smooth ride, making them suitable for high-speed trains.
    • Infrastructure: Standard gauge railways often have more extensive infrastructure and better connectivity due to their widespread use.

Narrow Gauge

  1. Definition: Narrow gauge railroads have a rail distance smaller than the standard gauge. Common narrow gauges include 3 feet 6 inches (1,067 mm), 3 feet (914 mm), and 2 feet (610 mm).
  2. Prevalence: Narrow gauge railroads are less common globally but are often used in specific regions, industries, or for particular purposes.
  3. Advantages:
    • Cost-Effective: Narrow-gauge railways are generally cheaper to construct and maintain, making them ideal for regions with challenging terrain or lower traffic volumes.
    • Tighter Curves: Narrow gauge tracks can handle tighter curves and steeper gradients, making them suitable for mountainous or rugged areas.
    • Flexibility: They are often used in industries such as mining, logging, or agriculture, where flexibility and lower costs are more critical than speed and capacity.


  • Standard Gauge: Used in most major rail networks, including passenger services, high-speed rail, and heavy freight operations.
  • Narrow Gauge: Found in specialized environments such as mountain railways, industrial railways, heritage railways, and some regional lines.


  • Standard Gauge: Most North American rail networks.
  • Narrow Gauge: The Carson Colorado Railroad (3 feet gauge)

In summary, while standard gauge railroads offer advantages in interoperability, stability, and infrastructure development, narrow gauge railroads provide cost-effective solutions and greater flexibility in challenging terrains or specialized applications.

Bear Lake, Baldwin Lake and Big Bear Lake

In the summer of 1845, Benjamin D. Wilson, who owned part of the interest in the Jurupa Rancho, the site of the present city of Riverside, led a troop of Calvary in search of cattle rustlers.

Setting out from San Bernardino Valley, he divided his command. Most of the men he sent through Cajon Pass, keeping only 22 Mexican troopers with him to follow a trail across the mountains. Two days later, Wilson and his men reached the lake, where they sighted scores of grizzly bears.

Big Bear Lake

Most of the soldiers had been vaqueros. They formed in pairs and drew reatas, each pair attacking a bear. One looped a rope around the bear’s neck; his companion roped the same bear by a hind foot. Then, the men drew apart to stretch the rope taut and hold the bear a prisoner. They bagged and skinned eleven bears, stretched their hides, and continued across the mountains to join the rest of the command on the desert at Rancho Las Flores, on the Mojave River.

Here, the reunited party engaged Indians in a fight, after which Wilson and his 22 vaquero-troopers returned home by the lake. They again found the place overrun with bears, and the same 22 soldiers brought in eleven more bears—enough to give them a bear rug apiece as a trophy. It was then that Wilson gave the little body of water the name Bear Lake.

Years later, the name was changed to Baldwin Lake. The name survives, however, in Big Bear Lake, which was created at the site of the Talmadge Ranch in 1884, when a dam was built to provide a constant water supply for the Redlands District.

Adapted from ~ Pioneer Tales of San Bernardino County – WPA – 1940.