Gabrielino Loop

Brown Mountain Loop is a 13.5 mile moderately trafficked loop trail in the foothills of the San Gabriel Mountains near Altadena, California. The trail consists of single and double track dirt and is popular amongst hikers, trail runners, and mountain bikers. This loop is a local favorite! The trail features wildflowers, expansive views of the San Gabriel Valley, and several water crossings. It begins with a challenging uphill but ends with a long, rewarding and scenic descent. There are multiple options for starting points and multiple places for parking. The main parking lot for the Arroyo Seco is off of Arroyo Seco road. The route described here starts in a neighborhood with ample street parking along Altadena Road. Park at the end of Altadena Road, this is a dead end road. Where the road ends, the trail begins. Take the obvious connector trail down to the Arroyo Seco. The Arroyo Seco Trail begins on wide pavement. Within the first mile you enter Fern Canyon and connect to the Gabrielino Trail. Fern Canyon is a nice wooded area and here your paved road becomes a dirt trail. After two miles you will reach Gould Mesa Camp which has vault toilets if needed. The steepest part of the climb begins once you reach 4.5 miles and tops off at 6 miles. It's all downhill from here! As you enjoy your smooth descent trail runners should be mindful that this section is very popular amongst mountain bikers. Proceed with caution. Other than the bike hazard, the descent is a great run or hike with scenic views and the terrain is not too steep.