Horsetooth Reservoir

Horsetooth Reservoir is Fort Collins' backyard playground—a 6.5-mile body of water nestled against the foothills just west of town. The distinctive rock formation that gives it its name (it does look like a horse's tooth) towers above the western shore. For residents, Horsetooth is the default answer to "what should we do today?" on any sunny weekend.

The reservoir offers something for every outdoor interest: beaches for swimming, boat ramps for watercraft, trails for hiking and mountain biking, and rock formations for climbing. Managed by Larimer County, it's a well-maintained facility that sees heavy use from May through September, with year-round activity for hikers and mountain bikers.

Water Activities

Swimming is permitted at designated beaches along the reservoir's eastern shore. Inlet Bay and South Bay have the most developed beach areas with restrooms nearby. The water is cold early in the season (snow-fed reservoir) and warms to comfortable temperatures by mid-July.

Boating ranges from kayaks and paddleboards to powerboats and jet skis. Multiple boat ramps provide access. Rentals are available at the marina—kayaks, paddleboards, and pontoon boats for those without their own watercraft.

Fishing produces walleye, bass, and trout depending on season and location. The reservoir is stocked and sees significant fishing pressure, but knowledgeable anglers still do well. Early morning and evening are most productive.

Scuba diving is popular given the reservoir's clarity and depth. Several dive shops in Fort Collins offer certification courses that include Horsetooth dives.

Hiking & Biking

Horsetooth Mountain Open Space flanks the reservoir's western shore, offering trails with significant elevation gain and views of the Front Range. The hike to Horsetooth Rock (the namesake formation) is the signature trail—challenging but rewarding.

Lory State Park connects to the northern end, extending trail options considerably. The combination of Horsetooth Mountain and Lory creates a substantial trail network for hikers and mountain bikers.

Mountain biking terrain includes technical singletrack and smoother doubletrack options. The trails see heavy use, so expect to share with other users. Weekday mornings are quietest.

Trail running is popular, with loop options ranging from 3 to 15+ miles depending on how much you want to connect.

Rock Climbing

Horsetooth Reservoir is a legitimate rock climbing destination, with routes on the distinctive sandstone and granite formations around the lake. Rotary Park on the eastern shore has beginner-friendly routes; Duncan's Ridge and other areas offer more challenging terrain.

Difficulty range spans from easy top-rope routes to serious trad leads. The rock quality varies—some areas are solid, others require care with loose holds. Local guidebooks and climbing shops can point you to appropriate routes for your level.

Bouldering is also available, though the area is better known for roped climbing.

Camping

Campgrounds dot the reservoir's shoreline, offering sites with water views. Inlet Bay Campground is the largest. Sites range from tent-only to full RV hookups. Reservations are essential for summer weekends—the campgrounds book up weeks in advance.

Amenities include restrooms, picnic areas, and fire rings. Some campgrounds have shower facilities. It's developed camping, not backcountry, but the location and views compensate.

Practical Information

Fees: Larimer County requires a vehicle pass for entry. Daily and annual passes are available at entrance stations and online. Annual passes pay for themselves quickly if you're a regular visitor.

Crowds: Summer weekends are very busy. Arrive early for parking at popular areas. Weekdays and mornings offer more solitude. The reservoir is big enough that you can usually find space, but popular spots get crowded.

Water levels: The reservoir level fluctuates based on irrigation demand and drought conditions. Low water years may limit some boat ramp access. Check current conditions before launching larger watercraft.

Weather: Afternoon thunderstorms are common in summer. Get off the water when storms approach—the reservoir is exposed and lightning is a real risk.