There are three geographical subspecies: Sciurus griseus griseus (central Washington to the western Sierra Nevada in central California); S. g. nigripes (from south of San Francisco Bay to San Luis Obispo County, California; and S. g. anthonyi, which ranges from San Luis Obispo to northern Baja California).
Unity of command is ensuring unity of effort under one responsible person (or commander) for completing a task. This unity of command is one of the twelve principles of joint operations, and is defined as:
Unified combatant command. A unified combatant command (UCC) is a United States Department of Defense command that is composed of forces from at least two Military Departments and has a broad and continuing mission.