Trail starts at Upper Arroyo Park, goes under the 210 freeway to Devil's gate dam, then crosses the dam and goes back under the freeway via Flint Wash, and follows the wash to Cherry Canyon park, then the real uphill starts as we climb to Cerro Negro peak which looms over the Descanso Gardens botanical park. Then we return via a different loop down to Flint wash and follow the same route back.