The Eastern San Juan Mountains
Their Geology, Ecology, and Human History
Publication Year: 2011
Published by: University Press of Colorado
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As a Colorado native and lifelong outdoorsman, it doesn’t take much to get me to boast about my home state. The duties of governor have taken me to the four corners of Colorado and around the country, so I can say with authority that the San Juan Mountains epitomize what...
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This volume is the companion to The Western San Juan Mountains: Their Geology, Ecology, and Human History, which was published in 1996. The earlier volume includes chapters that focus on all of the San Juan Mountains, and the same is true for this book. Although both volumes...
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Part 1: Physical Environment of the San Juan Mountains
1. A Legacy of Mountains Past and Present in the San Juan Region
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Throughout time, people have been drawn to mountains for inspiration, recreation, and scientific exploration. Mountains are also vast warehouses of natural resources and libraries of geologic history. ...
2. Tertiary Volcanism in the Eastern San Juan Mountains
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Andesitic to rhyolitic volcanic rocks of the San Juan Mountains, along with associated epithermal ores, were studied intensively during the twentieth century (e.g., Larsen and Cross 1956), culminating with detailed study of the Creede Mining District by Steven and Ratté (1965) as well as regional...
3. Mineralization in the Eastern San Juan Mountains
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The eastern San Juan Mountains were less intensely mineralized than the western San Juans; in addition, the styles of mineralization were less diverse and the time interval of mineralization was shorter. Nevertheless, mines in the eastern San Juans produced more than $375 million of...
4. Geomorphic History of the San Juan Mountains
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The San Juan Mountains encompass 6,000–7,000 mi2 (15,000–18,000 km2) and thirteen peaks that rise above 14,000 feet (4,267 m). Some of these “fourteeners” are flanked by valley floors as low as 7,000 feet (2,133 m). The surface of the...
5. The Hydrogeology of the San Juan Mountains [Includes Image Plates]
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Knowledge of the occurrence, storage, and flow of groundwater in mountainous regions is limited by the lack of integrated data from wells, streams, springs, and climate. In his comprehensive treatment of the hydrogeology of the San Luis Valley, Huntley (1979) hypothesized...
6. Long-Term Temperature Trends in the San Juan Mountains
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Temperatures in the San Juan Mountains are highly variable in both time and space. During a single day, temperatures in the high mountains can vary from well below freezing to above 15°C (60°F). Large extremes can also occur in the lower-elevation, more arid regions of southwestern Colorado. ...
Part 2: Biological Communities of the San Juan Mountains
7. Mountain Lakes and Reservoirs
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Ecological processes and species occurrences within most ecosystems in the semiarid western United States are limited, in some way or another, by moisture. Aquatic ecosystems are obvious exceptions. The Western San Juan Mountains focused on flowing (or lotic)...
8. Fens of the San Juan Mountains
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Types of mountain wetlands include marshes, riparian areas, wet meadows, fens, bogs, and salt marshes (Carsey et al. 2002). However, fens are the dominant wetland type above 9,000 feet (2,700 m) in the San Juan Mountains (Chimner, Cooper, and Lemly 2010). The fen is a distinctive wetland...
9. Fungi and Lichens of the San Juan Mountains
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The kingdom Eumycota is composed of fungi—heterotrophic, terrestrial organisms that are evolutionarily more closely related to the animal kingdom than to any of the other life forms on Earth. Fungi often appear similar to plants, but they are not photosynthetic; instead, they must...
10. Fire, Climate, and Forest Health
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While driving from Pagosa Springs to South Fork over Wolf Creek Pass, we cannot help but notice changes in the vegetation that blankets the spectacular mountain scenery. The vegetation in the San Juan Mountains is dominated by different forest types, assemblages of species...
11. Insects of the San Juans and Effects of Fire on Insect Ecology
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Hidden beneath the austere beauty of the rock, water, soil, trees, and plants of the San Juan Mountains and environs lies a complex community of insects whose lives have shaped the habitats of this architecturally diverse ecosystem. Insects and their life cycles, feeding habits...
12. Wildlife of the San Juans
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This chapter describes a few species of wild animals that occur in southwestern Colorado. What makes these species’ existence and natural histories in the San Juan Mountains noteworthy when any of hundreds of other species and their unique stories could have been chosen? ...
Part 3: Human History of the San Juan Mountains
13. A Brief Human History of the Eastern San Juan Mountains
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The eastern San Juan Mountains include some of the most rugged terrain in the United States. Within these “Shining Mountains” lie Ute vision-quest sites, old trails and mines, stock driveways, and so few roads that, in 1975, Congress established the Weminuche Wilderness...
14. Disaster in La Garita Mountains
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John Charles Frémont’s fourth expedition into La Garita Mountains at the eastern fringe of Colorado’s San Juan Mountain Range (1848–1849) bears all the intrigue found in classic Greek drama. The hero, Frémont, had become a popular champion among his countrymen. ...
15. San Juan Railroading
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“The difficult problem of our prosperity will then be solved, and we will then have to thank the enterprise and pluck of the much-maligned narrow gauge,” asserted Silverton’s San Juan Herald (April 27, 1882). The long-awaited arrival of the Denver and Rio Grande Western Railroad...
Part 4: Points of Interest in the Eastern San Juan Mountains
16. Eastern San Juan Mountains Points of Interest Guide
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This road log is meant for the visitor who wishes to further explore the geology, ecology, and human history, as seen from the highways that traverse and circumnavigate the eastern San Juan Mountains. This guide is designed so the traveler can enter a given highway at any point and travel in either direction. ...
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Page Count: 416
Illustrations: 100 b&w photos, 33 color illustrations, 21 maps, 12 tables
Publication Year: 2011