I stayed in Fontana for about a week in April 2015 and enjoyed the prevalence of small mountains in the area. I hiked up Mt. Jurupa twice. The second time I bushwhacked down the west slopes to also climb Peak 1802, which has some nice boulders on the summit as well as a surprising amount of vegetation. I also hiked up a 1,602-foot peak not far to the east of Jurupa, called Rattlesnake Mountain on old topo maps. It was unremarkable, but I climbed it for its name. Slightly more interesting were Peak 1452 to the southeast of Rattlesnake Mountain, and Peak 1739 to the south. More recently I hiked up Peak 1913, just east of Mt. Jurupa.