Trampas Canyon is a short tributary of San Juan Creek in southern Orange County the U.S. state of California. It rises in forks on steep slopes of the southern Santa Ana Mountains (33.4883597°N 117.5933813°W), and flows north to where it is dammed by Trampas Canyon Dam (USGS San Clemente Quad 7½"). Trampas Canyon 1795-006 Dam (33.498359°N 117.587548°W) forms a small lake that branches into four forks running east-west. Exiting the dam, the creek flows north and turns slightly to the west, where it joins San Juan Creek on the left bank, near the confluence of Cañada Gobernadora (33.3053°N 117.3458°W).