The locations of the missions were all very planned and very deliberate. Each mission was placed one day's ride or hard walk from its nearest neighbors. This made it easier for the Spaniards to trade and sell their food and crafts as well as to share information. They were also very careful to place all the missions near the sea so that ships would have plenty of opportunities to get fresh supplies before heading out to sea.
Many of the missions were placed along Native American trails. The reasons for this were simple: The Spanish knew that the Native Americans always made their trails near fresh water and fertile soil; two things that the Spanish needed for succesful missions. Another reason for the choice of native trails was the fact that it would make recruiting people even easier.