5.9 mi of trail, end to end · about 1,800 ft of climbing · 8,492 ft–9,408 ft · native surface · trail class Minimally Developed · bike, hiking, horse · seasonal: Winter seasonal closure dependent on current conditions
TrailheadAlamo Canyon Trailhead 8,497 ft Drive there
Hike the Sulphur & Alamo Canyon Loop the Park Service's write-up
6-8 Hours · no dogs · entrance fee applies · Spring, Summer, Fall
Start Sulphur & Alamo Canyon Loop
Alamo Canyon features several geothermal ponds. Photo: NPS/L. Ray
This strenuous, 12.2-mile (19.6 km) trail follows Sulphur Creek, passing through an old sulphur mining area, before turning eastward to skirt beautiful Valle Seco. It slowly climbs the ridge at the edge of Valle Seco before dropping back down Alamo Canyon, passing three geothermal ponds along the way. Best hiked clockwise. GPS required, especially for Alamo Canyon.
Elevation: 8,069 - 9,392 feet
Accessibility This unpaved, natural surface trail has steep grades. Service animals permitted.
The lines are the National Park Service's public trails layer, the trailheads and the waterfalls, views, peaks and historic places along them the Service's public points of interest, read 2026-10-16 and simplified for the map; the length is the line's, end to end. The write-ups are the Service's own "things to do" text, unedited. Heights come from USGS 3DEP through Terrain Tiles on AWS (Mapzen/Tilezen), read along each line and rounded; a short trail on steep ground can be off by a few tens of feet. Closures change: check the park's own site before you go.
