Horsetooth Mountain Open Space charges an entrance permit

Horsetooth Mountain Open Space rises above the west side of Horsetooth Reservoir, and it is named for the notched rock on the skyline that looks like a horse’s tooth from town. It is a popular spot for hiking and biking, with trails climbing to Horsetooth Rock itself and out to Horsetooth Falls, a waterfall that runs best in spring.

One thing to sort out before you go is that this is a Larimer County open space, and an entrance permit is required. You buy a daily or annual permit, usually at a self-serve station at the trailhead, and the requirement applies at the Soderberg Trailhead too, not just the main lot. The reservoir below is a separate county park area with its own pages covering entrance fees, boat inspections, and camping, so check the Larimer County page for the specific entrance and activity you have in mind rather than guessing.

The trails here gain real elevation. The loop to the falls and the route up to Horsetooth Rock are both worthwhile, but they are uphill work, and the upper rock is a scramble at the very top. Drinking water is usually available at the main trailhead, but bring your own to be safe, and start early on summer weekends because parking fills.

For current permit prices, trailhead hours, and trail conditions, see the Larimer County Horsetooth Mountain Open Space page.