Rancho Trabuco was a 22,184-acre (89.78 km2) Mexican land grant in present-day Orange County, California. The five square league grant consisted of two square leagues given in 1841 by Governor Juan B. Alvarado to Santiago Argüello plus three square leagues given in 1846 by Governor Pío Pico to John (Don Juan) Forster.[1] The name "trabuco" means "blunderbuss" in Spanish. The grant extended along Trabuco Creek and Trabuco Canyon, and encompassed present-day Coto de Caza.[2] The grant was bordered by Rancho Cañada de los Alisos on the west, and by Rancho Mission Viejo on the east.[3]