The RTS Loop Trail is located below the Utah Olympic Park. You can find the trailhead and accompanying parking lot on Olympic Parkway, right across the road from the Run-A-Muk trail. You can also access the loop from the Millennium Trail behind the outlet mall in Kimball Junction, making it a nice little work out before or after a day of shopping. This 2.6 mile loop is one of the less frequented trails in town, but perfect for anyone wanting a quick, easy jaunt into the outdoors without too much commitment.
The upper portion of the trail, closer to the UOP, is partially shaded by groves of aspen trees while the lower section is primarily sage- and brush-covered hills. The trail is very well-maintained and impossible to get lost on. With less than 200 feet of vertical difference between the loop's highest and lowest points, it's a great place for laid back hikers, small children, trail runners, or beginner (or out-0f-shape!) mountain bikers.
If you want to get an introduction to riding on dirt, this is the place. The RTS loop is very mellow compared to many other Park City rides, with easy slopes, a generous radius on all the turns, and an almost entirely smooth surface (there are a few small rocks here and there).
Thanks to the easy terrain, completing the loop on foot probably won't take you more than an hour, even at a leisurely pace. Bikers can swoop around even faster, but the trail is pleasant enough that you may want to do more than one loop. Since this is a single-track, if you do happen to be riding, remember it's recommended to ride the loop clockwise (going uphill from the trailhead) on even-numbered days and counterclockwise on odd-numbered days.
As you wind through the trees, you'll be privy to fantastic views of the surrounding area, especially if you opt for a sunset filled evening excursion. You can spy the UOP between the trees and even get a clear view in other areas. Near the top of the loop, there's a junction with a trail marker to either stay on the RTS Loop or continue onto more advanced trails heading up towards the UOP, including Iron Bill (which you can reach after a short uphill and crossing the pavement of Olympic Parkway).
During the winter, the RTS Loop is swallowed up by the larger Olympic Park 5K and is one of Park City's free winter trails, regularly groomed by Basin Recreation. But winter usage is strictly for cross-country skiers (no dogs, snowshoes, pedestrians, or bikes allowed). Summers are, of course, open to everyone!