Here's a loop that you can do from Chantry Flats which is above Arcadia, CA, that goes up to Spruce Grove and Hoegee's trail camps. This can be done as a day hike as well, but for gear checkouts, it makes a nice hike, and its very accessible. Hoegee's is in my opinion over used, but Spruce Grove only had one camper in it when I was there on Saturday.
If you want a little longer loop, take in the Summit of Mt. Wilson which will add about 7 more miles IIRC.