Complex sentence: Private landowners sold land northeast of the lake to the University of California in 1966, creating the James Reserve, and the Banning-Idyllwild road was designated California State Route 243 in 1970.
Split into simpler sentences: Private landowners sold land northeast of the lake to the University of California in 1966, creating the James Reserve. The Banning-Idyllwild Road was designated California State Route 243 in 1970.