You mentioned Mammoth Lakes. If you do stop in the Mammoth area there are several hikes that meet your criteria.
1. Crystal Lake. Trail head is at Lake George and I would expect the road to be open (although a late storm could change that). One way distance to the lake is a bit over one mile, but you can also hike the length of the lake, with many picnic spots along the way. Total round trip distance including the length of the lake is ~ 3+ miles, with approx. 600' elevation gain.
2. A bit further, and higher to climb, you could take the same trail, but turn right once you near Crystal Lake, and this would take you up to Mammoth Crest. Fabulous views, certainly a good workout. Approx. 2 miles and 1400' climbing. Because of the altitude, and exposed crest, snow could be a problem.
3. If the road to Reds Meadows is open there are many many more options.
Crystal Lake:
Mammoth Crest:
Links:
http://discovermammoth.com/2012/06/29/crystal-lake-mammoth-lakes-basin-california/http://discovermammoth.com/hiking/
