Lytle Creek is a census-designated place in the San Gabriel Mountains, within San Bernardino County. It is about 16 miles northwest of downtown San Bernardino and 10 miles from the cities of Fontana and Rialto. This small remote community is located in a large southeast-trending canyon on the eastern portion of the San Gabriel Mountains completely withi…Lytle Creek is a census-designated place in the San Gabriel Mountains, within San Bernardino County. It is about 16 miles northwest of downtown San Bernardino and 10 miles from the cities of Fontana and Rialto. This small remote community is located in a large southeast-trending canyon on the eastern portion of the San Gabriel Mountains completely within the boundaries of the San Bernardino National Forest. The population was 701 at the 2010 census.