Hartman Rocks Recreation Area has a large network of trails just outside of Gunnison, CO. During March 15 - May 15 each year about half of the park is closed for protected sage grouse.
Upper Loop (~19 miles): Josh Eberly recommends the following loop as the "best half of Hartmans you could do without crossing in protected Sage Grouse area":
Started at the base area parking lot of Hartman Rocks, on the east southeast side of the parking lot. There is a trailhead over there. Ran on the trail right behind the parking lot trail to Jacks. When I got to the top of Jacks, I was on Hartman Rocks Rd, I rand down the road and turned right on the connector to get to Tail Pipe. Tail Pipe to the The Ridge, and all the way down to the bottom of Top of the World. Then started climbing Top of the World. Top of the World goes for a while and ends at the Golfcourse Overlook Road, I turned left there and took that to Graceland. I took Graceland all the way to Gateway. Gateway to Josies, Josies to Buddy Bear. I took Buddy Bear to Cottonwood Grove Rd , ran down the road until Broken Shovel. I ran Broken Shovel down until I got to Joshos and took Joshos all the way to Rattlesnake. Rattlesnake merged into Top of Becks Road and eventually took a right down Becks. Ran right to the Notch until Backbone, and then Backbone to the connector to Kids until I ended at the same exact spot I started. It seems complicated, but the trail system is very simple, big signs and ALL of them run into each other.