The 224 soldiers and airmen have completed their training at Camp Roberts and will accompany Border Patrol agents in the field before going fully operational next month.
The troops are part of a 1,200-person National Guard deployment to the U.S.-Mexico border ordered by President Obama. Their mission is to interdict illegal immigrants and drug smugglers entering the United States.
"I am proud to say that we are the first state to have our troops trained and operational for this mission," Schwarzenegger said in a written statement.
The governor's office said the National Guard troops will monitor remote crossing points and also carry out duties such as analysis and entry identification.