This is a challenging but beautiful route starting at the beach in Santa Barbara and climbing through the Santa Ynez mountains to La Cumbre Peak and then back. It is roughly marathon distance (~ 26 miles) and has more than 8,200 feet of vertical change--almost no flat running.
The route is a simple out-and-back route, following the Pier-to-Peak half marathon route: https://www.halfmarathons.net/course-map-pier-to-peak-half-marathon/ (but without the quick 0.1 mile up and back when you first hit Camino Cielo). It starts at the dolphin fountain on the beach right in front of Stearns Wharf. Proceed up State street for a few blocks and take a right on Haley street. Two blocks later, take a left on Santa Barbara street and follow that up several miles to Mission street, at which you take a right. Then take a left at Laguna street and then a right on E. Los Olivos street. Just after passing by the Santa Barbara Mission, take a right on Mountain Road and follow that several miles up and behind the Riviera to Gibraltar Road. Take Gibraltar Road up the mountains for 6 or 7 miles to Camino Cielo. Take a left on Camino Cielo and proceed up to La Cumbre Peak lookout station at an elevation of 3,396 feet. Then follow the exact route back to the Dolphin fountain at State Street and Cabrillo, at the base of Stearns Wharf.