San Juan County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 705, making it the least populous county in Colorado. The county seat and the only incorporated municipality in the county is Silverton. The county name is the Spanish language name for "Saint John", the name Spanish explorers gave to a river and the mountain range in the area. With a mean elevation of , San Juan County is the highest county in the United States and also has the two highest elevation houses in the United States; the ‘Bonnie Belle’ above Animas Forks at 11,900’ – 11,950’ elevation and an unnamed house above Picayune Gulch at 12,000’ elevation.
History
Long before European settlement, the area was regularly explored by the Anasazi, and later the Utes, who hunted and lived in the San Juans during the summer. There is also speculation that Spanish explorers and fur traders ventured into the area in the 1600s and 1700s.
After the Brunot Agreement with the Utes in 1873, which exchanged for the Southern Ute Indian Reservation and $25,000 per year, several mining camps were constructed. These would later become the communities of Howardsville, Eureka, and Silverton. San Juan County was formed on January 31, 1876, from part of La Plata County.
The region boomed after George Howard and R. J. McNutt discovered the Sunnyside silver vein along Hurricane Peak, outside the mining camp of Eureka. Gold was then discovered in 1882, which helped the county weather the Panic of 1893 far better than other mining communities, such as Aspen or Creede.
Mining operators in the San Juan mountain area of Colorado formed the San Juan District Mining Association (SJDMA) in 1903, as a direct result of a Western Federation of Miners proposal to the Telluride Mining Association for the eight-hour day, which had been approved in a referendum by 72 percent of Colorado voters. The new association consolidated the power of thirty-six mining properties in San Miguel, Ouray, and San Juan Counties. The SJDMA refused to consider any reduction in hours or increase in wages, helping to provoke a bitter strike.
The Sunnyside mine was shut down after the 1929 stock market crash, but was acquired by Standard Metals Corp. in 1959, and reopened, finding gold in 1973 with the Little Mary vein. The county's economy was dealt a devastating blow in 1992 when the mine and the corresponding Shenandoah-Dives mill, the last operating in the region, permanently closed. It is the fifth-smallest county in Colorado by area. The county is located in the heart of the San Juan Mountains of Colorado. Though it has the highest mean elevation of any county in the United States, at , none of Colorado's 53 fourteeners (mountains at least 14,000 feet in elevation) are in San Juan County.
Adjacent counties
- Ouray County – north
- Hinsdale County – east
- La Plata County – south
- Montezuma County – southwest
- Dolores County – west
- San Miguel County – northwest
Major highways
- 20px U.S. Highway 550
300px|thumb|[[Silverton, Colorado|Silverton as seen from US 550]]
National protected areas
- Durango-Silverton Narrow-Gauge Railroad National Historic District
- Rio Grande National Forest
- San Juan National Forest
- Shenandoah-Dives (Mayflower) Mill
- Silverton National Historic District
- Uncompahgre National Forest
- Weminuche Wilderness
Trails and byways
- Alpine Loop National Back Country Byway
- Colorado Trail
- Continental Divide National Scenic Trail
- San Juan Skyway National Scenic Byway