Missionaries / Missionary Life / Franciscans

Do you know of a book or archive that ever had or published an image of Fr. Jose Altamira?

I have never seen reference to a contemporary image of Jose Altamira. If there was one it would have been a drawing or painting. My suggestion is that your nephew draw a picture of him. He arrived at Monterey in 1820, age 33. He did not make a favorable impression.

Can you help me find a picture of Father Jose Cavaller of Mission San Luis Obispo?

There are very few images of the mission era Franciscan friars. Remember that they lived well before the advent of photograph. If an image survived it had to be painted or drawn as was done with Fr. Junipero Serra when he was in Mexico City for a visit.

Who founded Mission Santa Cruz?

Santa Cruz was founded on August 28, 1791 under the overall leadership of Fr. Fermin Lasuen, the second Father President of the mission chain. The founding missionaries (the men who were responsible for building the mission day-in and day-out in its initial years) were Fr. Isidro Salazar and Fr. Baldomero Lopez.