In Altadena, Los Angeles County, the Echo Mountain trail via the Sam Merrill Trail offers a captivating adventure for hikers and their dogs. This hike in the lower San Gabriels treats visitors to breathtaking vistas, forested mountain canyons, and the fascinating ruins of a turn-of-the-century mountaintop resort that once operated as a destination hotel and observatory.

History enthusiasts will find plenty to explore along the way. Numerous plaques and markers dot the trail, providing insight into the area’s rich past. You’ll encounter remnants of an old railroad that once traversed these mountains, reminders of when this was a popular tourist destination in the late 1800s. The structures and artifacts scattered throughout make it feel like you’re walking through a preserved piece of Southern California history.

For dog owners, the Sam Merrill Trail works well as a hiking route. The moderate difficulty level and well-maintained paths make it accessible for most dogs, offering a solid shared adventure in the mountains without being overly strenuous. The elevation gain is steady but manageable, and the shade from the forest canopy helps keep things cooler during the hike.

The trail itself is roughly four and a half miles round trip, so plan accordingly depending on your dog’s fitness level and the heat. Summer afternoons get hot in this area, so early morning starts are wise. Bring plenty of water for both you and your dog—the trail doesn’t have water sources along the way. The views from Echo Mountain itself are worth the effort, offering sweeping perspectives of the San Gabriel Valley and a genuine sense of accomplishment when you reach the old resort ruins. The combination of history, scenery, and accessible terrain makes this a solid choice for a dog-friendly day hike in the San Gabriels.