The 8.8 mile Perimeter Trail winds around Barr Lake. The trail across the top of the dam is closed on Wednesdays and Saturdays during waterfowl hunting season (October - February). There are many short boardwalks and loop trails connected to the Perimeter Trail. Bicyclists beware of goatheads that can pop tires. Thorn-proof tubes are recommended. Horse riders beware of new steep grade section of concrete at the East end of the Dam (MP-7).