Potato Mtn - Wilderness Trail is a 5.8 mile out and back trail located near Claremont, California that offers scenic views. This track is connectable from the Claremont Loop or Marshall Canyon Trail. I understand you can head up Every Canyon as well, but heard you need a pass (free) to get on the trail.
This trail is primarily used for hiking, road biking & trail running. Connecting from Marshall Canyon Trail will provide quite a workout, as it's 8 to 9 miles of climbing. I wouldn't recommend this on a hot summer day as there is little respite from the sun. If coming up the Cobal Canyon - Claremont trail, you're looking at 5 to 6 miles. The trail is all fireroad and not very rocky at all. Additionally, the last dig up to the peak is a pretty good stretch and a bit steep. It's really the only tough section.
Once at the top, the tradition is to leave a spud with your name on it at the concrete cylinder at the peak. Once up there, you'll get some good views of the Pomona Valley and Pacific Ocean on clear days.