The San Juan Mountains are comprised of fourteen (14) counties that share portions of the mountain region. Within the San Juans, there are half a dozen mining towns that have transitioned from traditional industries in resource extraction, specifically mining, to recreation and tourism. The region is known for its geological, ecological, hydrological and climatological diversity.

The San Juans have several unique attributes when compared with mountain ranges world-wide. They are accessible, yet not close to population centers. Their geologic history, ranging from mid-Proterozoic metamorphic rock complexes to the extensive Phanerozoic sedimentary sequences (16,000 ft. section), to the geologically relatively recent San Juan volcanism (40-20 Ma), and finally to Pleistocene localized glacial activites, is as varied as that of any mountain range in the world.

They exhibit a wide diversity of ecological characteristics due to their mid-latitude location, wide range of elevations, and widely varying surficial geologic conditions (soils, slopes, rock types, etc.).This mountain range includes habitats and sensitive species found nowhere else in the world. The region is currently the last known location of certain arctic mosses, relics of the last ice age, and rare alpine fens. The range contains subalpine parks, grasslands and wetlands; nine stratified ecosystems including alpine, sprucefir, mixed conifer, ponderosa pine, oak and douglas fir; aspen forests; parks and meadowlands; mountain shrub communities; pinon-juniper woodlands; and shrub-steppe communities.

These ecological characteristics combined with their millennial history of human involvement (ancestral Puebloan populations, early explorations, extensive mining activties) means that they provde a wealth of opportunity for scientific investigation of questions related to their physical, biological and human environments. It also means there are a host of challenges to land managers and communities, related to resource use, recreation, remediation of past resource extraction, and other ongoing activities in close proximity to hazardous physical environments (rock slides, avalanches, forest fires). The San Juan Mountains contain six wilderness areas and are the headwaters for the Rio Grande, San Juan, Dolores and Animas Rivers.

The San Juan Mountains and margins are characterized by

• seven wilderness areas encompassing more than 800,000 acres (12 percent of the range) including Weminuche, South San Juan, La Garita, Mount Sneffels, Uncompahgre, Powderhorn and Lizard Head, including the most active avalanche control and snow physics study areas in the United States and is one of the most geologically diverse mountain regions in the world,
• one of the worlds largest Tertiary-age volcanic eruptions (La Garita ash-flow eruption, ~ 4,000 km3 circa 27 million years ago),
• some of the "cleanest" air found in the United States (U.S. Forest Service, 1999),
• active research in acid-mine drainage and water quality (Animas River watershed, Rio Grande watershed, Summitville),
• mineral resources that include uranium, gold, silver, copper, lead, zinc and molybdenum,
• energy resources that include, geothermal, coal, natural gas, and methane,
• Hesperus Peak that is one of the four Navajo peoples sacred mountains and adjacent Sleeping Ute Mountains,a sacred range of the Southern Utes and Ute Mountain Utes,
• abundant archeological sites at Mesa Verde National Park and proximal areas to the southwest,
• the first major mountain range for storm tracts moving from the southwest,
• on-going study area for more than a dozen university and college field camps.
• six ski areas, and home to people whose identities are strongly rooted in mountain history, culture and ways of living.

Most of the San Juan Mountains are under the authority of the San Juan, Rio Grande, Grand Mesa, Uncompaghre and Gunnison National Forests managed by the the US Forest Service and the Bureau of Land Management. The remaining lands are owned by private landowners, mining interests, cities, counties and the state of Colorado. This blend of diverse stakeholder interests lends itself to studies of land use conflict and how humans must resolve difficult issues associated with natural resource such as water, timber and minerals.