The men worked to prevent fires and fought some serious fires.  They erected phone lines and built bridges.  “During the life of the camp, 4,689 [person] days were spent in fighting forest fires and 14,232 in fire pre-suppression work”.  The latter included organizing, training, managing, equipping and maintaining fire suppression units.  Men cleared dead trees and brush as part of their prevention efforts. (Gingerich p. 139) 

Edwin J. Schrag from Kansas recalls his work at the camp.

Some of the work in California was to be fighting fires.  There were rumors that the Japanese were going to be sending hot air balloons or blimps over, loaded with fuels to start forest fires.  They needed men to be on hand to fight fires.  The work there was mostly cutting underbrush and clearing fire trails.  I worked in the experimental station studying erosion and rainfall.  A professor from the University of California was writing a book on the topic, and the statistics we recorded were in the book.  He could never have written his book without the work that the CPS men did, but when the book was published, there was no mention of how he obtained his statistics or information.  This all took place in the Sierra Vista Mountains near Visalia and Reedley, California.  We were about twenty miles from Yosemite National Park. (The Eden Peace Witness: A Collection of Personal Accounts pp. 134-142)