Mission Names / Nicknames / Basis for Naming / Meaning of Names

What were some of the nick names for the San Luis Obispo mission and why?

San Luis Obispo de Tolosa was the fifth mission. It didn't have a widely used descriptor like San Juan Capistrano (Jewel of the Missions)or Santa Barbara (Queen of the Missions). Its name was typically shortened to San Luis Obispo which of course became the name of the town. There were lots of grisly bears in this area in 1772 (when the mission was founded) and they named the area The Valley of the Bears.

Is there a list of all the nicknames used for each mission.

Here is a list of mission abbreviations in common use and the special 'designations' that Fr. Zephyrin Engelhardt, O.F.M. cited in his definitive multi-volume study The Missions and Missionaries of California, and smaller books on specific missions:
San Diego de Alcala San Diego Mission Mother of the Missions

Why was San Diego called “The Plymouth Rock” of the west coast?

San Diego was the name given the bay, the presidio (fort), the mission built on Presidio Hill overlooking the bay and the town that developed along the bay. The reference you make is to San Diego, not the San Diego mission.

Plymouth Rock is a granite boulder with the date 1620 carved on it. The rock lies near the ocean in Plymouth Massachusetts. When the arly English settlers of Massachusetts landed for the first time, in December 1620, tradition has it that they stepped ashore on this rock (or more likely, historians say, near this rock).

How was the San Jose Mission site discovered and who named the mission?

San Jose was founded by Father-President Fermin Lasuen, who succeeded Junipero Serra as head of the mission chain. He wanted to fill in the gaps between the established missions and planned to establish five new missions.

An exploratory party of six or seven men accompanied by a padre from San Antonio de Padua was assigned to find a good site for one of these missions in the area below San Francisco. The party traveled northeast from the existing mission of Santa Clara. The picked out the site pretty quickly, but actual approval and funding took a couple more years.

How were the California Missions named?

They were named by the founding missionaries in honor of a saint. As Donald Toomey, in his marvelous book The Spell of California’s Spanish Colonial Missions has pointed out, the act of naming “allowed the community settling there to Hispanicize and Christianize” the wilderness. The name chosen inserted the mission into the liturgical calendar. Each mission held a fiesta on the Saints day.

Why is the Mission San Diego de Alcala called the "Mother of all Missions?

The origins of the “official” name for first California mission (San Diego de Alcala) and the reference to this as the “Mother of all Missions” is a little convoluted. San Diego Bay was discovered by Juan Rodriquez Cabrillo in 1542 but given its present name by Captain Sebastian Vizcaino when he explored the coast in 1602. The name was subsequently applied to both the first Spanish presidio (fort) and the first mission in Alta California by Fr. Junipero Serra at the official founding of the mission, on July 16, 1769.

Does San Juan Bautista have a nickname?

Some of the missions had long, complicated names that were often shortened. For example, San Fernando Rey de Espana is usually referred to as ‘San Fernando Rey’ or’San Fernando.’ A couple missions have alternate names. San Francisco de Asis, is commonly called Mission Dolores (originally named after a stream that passed by). San Francisco Solano is also referred to as Mission Sonoma (for the town in which it is located).