Geology: Ice Cave Loop, Pagosa 5/21

Fissuring Out the Past

Join San Juan Mountains Association and the San Juan National Forest Pagosa Ranger District for our first 2026 interpretive geology hike. 

When you hear the term “ice cave”, thoughts of dripping ice-encrusted stalactites clinging to the icy blue ceiling of a glacial cavern may come to mind. This hike is not that, yet it’s fascinating in its own right. Not really caves, these are more like giant cracks; fissures in the underlying Dakota sandstone. Varying in size from one to eight feet wide, up to a hundred feet long and 30 feet deep, these chasms are cool year-round and often hold snow well into the summer. Layers of rock tell a story as old as time. Your guide will briefly explain regional geology and Morrison, Dakota and Mancos stratigraphy (Jurassic/Cretaceous) and also explain theory for the origin of ice caves. Included is a side hike to a stunning clifftop grand vista of the San Juan Mountains in the distance, and deep riparian river valleys below.

This is a loop route, partially off trail, with sustained, moderately difficult inclines/declines, on rocky terrain near high cliffs. Hike time is approximately 4 hours total, 3.5 miles round trip, and about 500 ft. vertical ascent. We will finish at the parking lot just after noon, and there is a picnic area nearby if you wish to bring your own lunch to eat after the hike.  We will have a snack break along the trail at a beautiful overlook spot.