Jackson Reservoir is a 3 mile lightly trafficked out and back trail located near Orchard, Colorado that features a lake. The trail is good for all skill levels and primarily used for hiking, walking, trail running, and fishing.
There is a 3.5 mile out and back walking/running trail starting at the visitor center. $7 entrance fee into the park. Pretty views of the lake. Trail did have a lot of bugs when I went a couple of weeks ago.