Mueller State Park is a 5,000 acre recreational area about a 45 minute drive from Colorado Springs. Among the myriad trail running opportunities, a highlight is the 3.3 mile Osborn Homestead Loop, where you can travel back in time to a historic Colorado homestead built in the early 1900s by the Earl Osborn family. Start out at the Black Bear Trailhead (Trail #13 on the map) and travel downhill to the Osborn Homestead (Trail #27). Continue to the homestead ruins and beyond on Trail #27 until it meets trail #13 again. Turn right and follow #13 back to the trail head. The linked map has information on the other trail opportunities in the park.
Notes: Great opportunity for wildlife viewing, but be aware. Also, in winter, trails might be used for snowshoeing or XC skiing.