Remsen, J.V. 1977 Rufous-crowned Sparrow Aimophila ruficeps May 26 East Mojave Desert, San Bernardino Co., Calif: I singing vigorously all morning on south-facing slopes of Live Oak Cyn in the exact same spot as last summer (slopes just above and east of the mine). June 20 East Mojave Desert : I collected (by S. Cardiff) in lower Keystone Cyn at ~ 5600 ft. as it sang on south-facing slopes covered with pinyon-juniper,