Eagle / Sage Loop is a 5.6 mile loop trail located near Boulder, CO. The trail is good for all skill levels and primarily used for trail running.
A very nice run with little huddle and nice views.
This is great loop for running, even better, you can string it together by starting at Wonderland lake and taking the Foothills Trail over to Eagle, then take Eagle out to 55th(the Boulder Reservoir road) head south to Jay rd. and then west through the NoBo Neighborhoods back to Wonderland Lake. I think it's like 12 - 13 ish miles.
Note: the location of the Eagle Trailhead is actually on the west side of Boulder Reservoir on 51st/55th Street. GPS coordinates: 40.080219, -105.235628
Moderate trail without much elevation gain and great views of the foothills.