 At the time of Sutter's arrival, Alta California was a province of Mexico and had a population of only about 1,000 Europeans and an estimated 100,000-700,000 Native Americans.Sutter had to go to the capital at Monterey to obtain permission from the governor, Juan Bautista Alvarado, to settle in the territory.Alvarado saw Sutter's plan of establishing a colony in Central Valley as useful in "buttressing the frontier which he was trying to maintain against Indians, Russians, Americans and British."