The missions were designed by the padres, and actually built by the Native Americans they hoped to convert. Each mission was unique in a few ways, but they all had the same basic plan: a large, four-sided building with a patio in the center. The church was usually placed in one corner of the square; it was always the tallest and grandest building. All the rooms in the square building faced the patio. The back was reserved for the unmarried native women who worked in the kitchen. The other three sides contained the rooms for the two priests of the mission, workshops, a kitchen, storage rooms for food, and the mission office. The rest of the Native Americans lived outside the mission walls in huts. Surrounding the mission were vast fields used for growing crops and feeding livestock.

The actual labor of the missions fell to the Native Americans. Because they practiced a polytheistic* religion, did not speak Spanish, had dark skin and a very different way of life, the natives were viewed as heathens; their way of life was considered inferior by the Spaniards. The Spanish made it clear that working on the missions was not optional*.