 The mountain whose southwestern flank is the creek's headwaters, known as "Kalawpa" by the indigenous peoples, was renamed Santiago Peak, after the creek.The Spanish left accounts mentioning the "Juaneño", the name given to the Acjachemen by the Spanish missionaries after the founding of Mission San Juan Capistrano, located to the southeast at the confluence of San Juan and Trabuco Creeks.One of the first settlers in the Santiago Creek watershed was Jose Pablo Grijalva, a former Spanish soldier, who arrived in 1784.