Multi-Year Road and Access Upgrades Continue at Carter Lake and Horsetooth Reservoir Through Winter
Larimer County will continue construction through the winter months on a federally funded project improving deteriorating roads and congested parking areas at Carter Lake and Horsetooth Reservoir, with multiple construction zones now between 5 and 85 percent complete.
The multi-year effort is partially funded through an $11 million federal grant from the Colorado Federal Lands Access Program, supplemented by $1 million from the Bureau of Reclamation's Federal Lands Transportation Program and $3 million in county matching funds. The Central Federal Lands Highway Division is managing construction, which began in spring 2025 and is expected to conclude in 2027.
Active construction includes improvements to Eagle Campground's main access road and parking lot at Carter Lake, now 50 percent complete. Work on the Quarry Day Use Area and overflow parking at Carter Lake has reached 85 percent completion, while new left-turn lanes along North County Road 31 are 5 percent complete.
Big Thompson Day Use Area improvements at Carter Lake stand at 20 percent completion. North Pines access road and parking lot paving at Carter Lake has reached 30 percent completion, while South Bay access road and parking lot paving at Horsetooth Reservoir is 50 percent complete. Inlet Bay access road and parking lot paving at Horsetooth Reservoir is 25 percent complete.
Turn lane expansion along West County Road 38E into South Bay at Horsetooth Reservoir is scheduled to begin in spring 2026.
Federal Programs Address Infrastructure Backlog
The Federal Lands Access Program was established in 2012 to improve transportation facilities that provide access to federal lands, with an emphasis on high-use recreation sites. Projects must demonstrate substantial public use and be owned or maintained by state, county or tribal governments.
Colorado receives approximately $10 million to $15 million annually through the program, distributed through a formula considering road mileage, number of bridges, federal land area and annual visitation to public lands, according to the Federal Highway Administration.
The Federal Lands Transportation Program provides additional funding directly to federal land management agencies for infrastructure within federally owned lands. The Bureau of Reclamation allocated $1 million from this program to supplement the Carter Lake and Horsetooth project.
Larimer County's 30-year open space conservation program, funded by a quarter-cent sales tax approved in 1995, has generated $355 million for land protection but does not typically cover major infrastructure reconstruction at Bureau of Reclamation reservoirs.
Facilities Show Effects of Heavy Use and Deferred Maintenance
Horsetooth and Carter Lake reservoirs attract more than 1.5 million visitors annually, ranking among the most visited reservoirs in Colorado and in the top ten statewide. The sites experienced particularly heavy use during COVID-era surges in outdoor recreation.
A 2018 Resource Management Plan documented widespread deterioration of paved access roads, campground loops and major parking lots, resulting in rutting, potholes and hazardous driving conditions. The plan identified overwhelmed parking infrastructure, insufficient capacity for peak demand periods and aging facilities as primary concerns requiring large-scale reconstruction.
Larimer County has operated, managed and maintained all recreation facilities at Horsetooth, Carter, Pinewood and Flatiron reservoirs since 1954 under an operating agreement with the U.S. Bureau of Reclamation. The reservoirs are part of the Colorado-Big Thompson Project.
Temporary Access Restrictions During Construction
Eagle Campground, North Pines, South Bay and Inlet Bay remain closed to visitor access due to ongoing construction. All motorized boating inspection stations are closed for the season.
Visitor centers at Horsetooth Reservoir and Carter Lake remain open Monday through Friday from 9 a.m. to 4 p.m.
The Larimer County Department of Natural Resources asked visitors to respect temporary closure areas and exercise caution near active construction zones.
Construction updates are available at engage.larimer.gov/flaphorsetoothreservoir. General information about Larimer County natural resources is available at larimer.gov/naturalresources.