Narrowleaf Lake Run

Narrowleaf Lake Run is held in Loveland, Colorado, on October 31, 2026, at Boyd Lake State Park. The distances run long on purpose: the Heavy 15K covers 10 miles at 8:00 a.m. with about 490 feet of climbing, the Heavy 10K is 7 miles at 8:30 a.m. with roughly 330 feet, and the Heavy 5K is 4 miles at 8:45 a.m. with about 160 feet. A 1 Mile Pumpkin goes at 9:00 a.m., and kids fun runs are on the schedule too.

The route is mostly paved path with a short off-road section, closed to car traffic, with lake views and wildlife along the way, and it is known for flat terrain that suits an even-paced effort. The name comes from the park's narrowleaf cottonwoods. The 10-mile option makes a strong half marathon rehearsal, run at goal half pace; the 4-mile is short enough for a first race. Just remember the distances are longer than their names suggest and pace accordingly.