Borell 1966 Ojo Sajma, Sierra del Frio 50200 ft. Chihuahua Mex. Apr 13 cont. mammal-cont. Jepus californicus - in mar.- april 1963 jackrabbits were scare but I were more abundant than cottontail. In 1963 an early morning or late every trips by car along the two mile road leading from this camp to the hunting ward would usually result in seeing one or maybe 2 jacks. In 1964 (apr.-may) two to three were commonly seen along this same stretch of road. I was not here in 1965. This morning on a trip up and back along this same little of road I counted 10 jacks.