The San Juan National Forest is a U.S. national forest covering over 1,878,846 acres in western Colorado. The forest occupies land in Archuleta, Conejos, Dolores, Hinsdale, La Plata, Mineral, Montezuma, Rio Grande, San Miguel and San Juan Counties. It borders the Uncompahgre National Forest to the north and the Rio Grande National Forest to the east. The forest covers most of the southern portion of the San Juan Mountains west of the Continental Divide. The forest contains two alpine wilderness areas; the Weminuche and South San Juan, as well as the Piedra Area. The Durango and Silverton Narrow Gauge Railroad passes through the National Forest.