San Juan is a county in Colorado, United States, in the San Juan Mountains of the southwestern part of the state. It had a population of 705 at the 2020 census, the fewest of any county in Colorado, and covers 387 square miles (1,002 km2) centred near 37°46′N 107°40′W.
Silverton is the county seat, and its postal code is 81433. The county has one incorporated town, three unincorporated communities, and one former mining camp now a ghost town. It sits in the Mountain time zone.
Towns & Villages in San Juan County
San Juan County has just five named places, and Silverton is the only one with its own municipal government. The rest are small unincorporated clusters or ghost towns along the Animas River corridor and its side gulches, most tied to the county’s 19th-century silver-mining boom. CDP = census-designated place; Unincorp. = unincorporated community with no formal boundary.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Silverton | Town · seat | 651 | 81433 |
| Howardsville | Unincorp. | — | 81433 |
| Middleton | Unincorp. | — | 81433 |
| Needleton | Unincorp. | — | 81433 |
| Eureka | Ghost town | — | 81433 |
Animas Forks, another former mining camp higher up the Animas River, is also sometimes listed for the county but has no year-round residents or services.
ZIP Codes
- 81433 — Silverton (also serves Howardsville, Middleton, Needleton and Eureka)
San Juan County is served by a single post office, in Silverton; every other named place in the county uses the same 81433 ZIP.
Geography
San Juan County sits entirely within the San Juan Mountains, one of the highest and most rugged ranges in the Rocky Mountain system. With a mean elevation of 11,240 feet (3,430 meters), it is the highest county in the United States, and the town of Silverton itself sits at over 9,300 feet in a high mountain basin. The Animas River rises in the county and flows south toward Durango.
San Juan County borders Ouray County to the north, Hinsdale County to the east, La Plata County to the south, Montezuma County to the southwest, Dolores County to the west, and San Miguel County to the northwest.
Demographics
San Juan County had 705 residents at the 2020 census, the smallest population of any of Colorado’s 64 counties. Silverton is by far the largest community and holds nearly all of the county’s population; Howardsville, Middleton and Needleton are small seasonal clusters with only a handful of year-round residents between them. Median household income data specific to the county is limited given its small population, but Colorado’s statewide median is the Colorado median of $92,911; San Juan County, with an economy centred on tourism and seasonal work rather than higher-wage sectors, generally trends below that figure. Population density is roughly 1.8 people per square mile, among the lowest in the state.
Economy & Local Life
Tourism and outdoor recreation now drive the county’s economy, built on the legacy of a mining district that once produced gold, silver, lead and zinc. The Sunnyside Mine, one of Colorado’s longest-running and most productive mines, operated near Eureka until it closed permanently in 1992, ending large-scale mining in the county. The Durango & Silverton Narrow Gauge Railroad, a coal-fired steam train that has run since the mining era, now carries visitors between Durango and Silverton through the Animas River canyon and is the county’s best-known attraction. Silverton Mountain, a backcountry ski area known for expert terrain, draws winter visitors, and the town’s historic Greene Street business district serves summer travelers headed over Red Mountain Pass or the Million Dollar Highway.
History
San Juan County was created on January 31, 1876, carved out of the much larger La Plata County ahead of Colorado statehood later that year. Spanish explorers had earlier applied the name “San Juan” (Saint John) to a river and mountain range in the region, and the county took its name from the range. Prospectors poured into the high basins around Silverton after silver strikes in the 1870s, and mining, followed by decades of hard-rock silver, gold and base-metal production, shaped the county’s towns, railroads and economy for more than a century until the Sunnyside Mine’s 1992 closure.
Getting There
U.S. Highway 550, known locally as the Million Dollar Highway between Ouray and Silverton, is the county’s only major road and its sole paved link to the outside world.
- Durango — 45 miles south
- Ouray — 23 miles north
- Ridgway — 33 miles north
- Telluride — 47 miles west
The nearest commercial airport is Durango-La Plata County Airport, south of Durango. US 550 over Red Mountain Pass and Molas Pass can close in winter storms, and the county has no rail passenger service; the Durango & Silverton Narrow Gauge is a heritage tourist line, not a commuter connection.
Frequently Asked Questions
Where is San Juan County?
San Juan County is in the San Juan Mountains of southwestern Colorado, between Durango and Ouray along U.S. Highway 550.
What is the population of San Juan County?
San Juan County had a population of 705 at the 2020 census, the fewest of any county in Colorado.
How big is San Juan County?
The county covers 387 square miles (1,002 km2), nearly all of it high mountain terrain.
What is the county seat of San Juan County?
Silverton is the county seat and the only incorporated town in the county.
How many towns are in San Juan County?
The county has one incorporated town (Silverton), three unincorporated communities (Howardsville, Middleton, Needleton) and one ghost town (Eureka).
What ZIP codes are in San Juan County?
The entire county is served by the single ZIP code 81433, based in Silverton.
Why is San Juan County called the highest county in the United States?
Its mean elevation is 11,240 feet (3,430 meters), higher than any other county in the country, because the entire county lies within the San Juan Mountains.
More counties in this state: Towns and villages in Colorado.