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":

It’s an official route for walking from rheine to Marsberg.
It is the Hermannsweg (about 160k) and the Eggeweg (about 70k)

https://hermannshoehen.teutoburgerwald.de/