When the Spanish settled the Carmel area in 1770 they built a presidio (fort) along the coast in Monterey, and in the beginning religious services were held at the presidio. However having the mission close to the presidio wasn’t desirable and it also soon became clear that the land along the coast was not particularly suited for growing crops.
Moreover there were relatively few Indians living near the presidio site. So, Fr. Serra personally traveled the area searching for a more suitable place for the mission, which he found in the fertile Carmel valley. Over time a substantial agricultural operation developed on the mission lands. Mission San Carlos Borromeo de Carmelo grew wheat (the mission ranked in the middle of all the missions in wheat production) and other crops such as corn, beans, peas, lentils and barley.
The Indians that occupied this area belonged to the linguistic group, the Costanoan, a term derived from the Spanish word costanos, which means coast people. Two other terms were used to designate the Indians in this large language group: Ohlone and Mutsun. According to the Handbook of North American Indians, Volume 8, the Costanoan-speaking people lived in approximately 50 nations or tribelets which ranged in size from 50 to 500 people. The neophytes at Carmel were drawn from these tribelets, in particular in the early years the Rumsen, who had five villages in the area where the Spanish landed and first settled.
Acorns were an important food for these natives (see of California Stories article “Acorns were Food Then”
You might be interested in this map of California Indians.