Constructed in 1906 as a mule corral, the Bunkhouse was converted into a dormitory in 1917 because the Ranch needed more worker housing. It boarded mainly house laborers and maintenance crew, and up to 50 men, with two to three per room, lived in the building at one time. Each small room had a different layout, custom closets, and unique shelving units built by its occupants. Another identical bunkhouse stood on Jeffrey Road at the Irvine's Harkleroad Camp citrus orchard. The building displays typical Craftsman architectural features, including a gabled roof, sash windows, exposed rafters, latticework at the attic vent, and right-angle roof support braces.