This lollipop loop is a popular route that starts at the Hahamongna Watershed Park. It is around 15 miles long with about 2,200 ft of elevation gain. The best place to park is at the Oak Grove Disc Golf Course (lower parking lot) at 4550 Oak Grove Dr, La Cañada Flintridge, CA 91011. 

TransQilian is a ~105km loop course through the Qilian mountain range in Gansu province at ~10,500ft average elevation going as high as 14,600ft. This is an established loop (there is an ultra race on it which was in its 5th edition in 2019).

Kendrick Peak outside Flagstaff, AZ, from the Kendrick Trailhead to the fire tower, via the Kendrick Mountain Trail.  The 7km ascent has a Strava Segment.