This is a fairly strenuous 10-mile loop that is just across the highway from Mammoth Lakes. It starts with a nice climb behind the geothermal plant, giving you an interesting perspective of the area. Long before the geothermal plant was built, this area was called Casa Diablo. At one time, there were hot springs and an active geyser here. It was a stagecoach stop around 1880, and tourist attraction in the 1920’s. Even earlier than that, Native Americans had an obsidian mine here. As you’re riding, look around at all the whitish areas on the slopes, created from geothermal activity of the Long Valley Caldera.
Archive photo of the Casa Diablo tourist area and geyser in the background
Another shot of the old Casa Diablo Geyser
Eventually you reach Antelope Springs Road and continue climbing this graded road before making a a right for a gorgeous descent down into the valley below. The views of Mt. Morrison and the Sierra Crest are magnificent. Before long, you turn right again, and start the climb to the Casa Diablo Overlook. As you get near the top, you’ll be riding over lots of beautiful obsidian. From the top, you can look west to Mammoth Mountain and see the geothermal plant below. You can look to the south to see Crowley Lake and Doe Ridge, while to the east Hot Creek and the Long Valley Caldera are visible. It’s a magnificent viewpoint and well worth the effort. Afterwards, you complete the loop with fun descent including some rarely ridden singletrack (super fun, with a couple bits of hike-a-bike).
A very similar route, that is longer and has some more climbing, is the Little Antelope Valley Loop. Big Smokey Loop and Little Smokey Loop are also related to this ride, and can be combined for an epic day in the saddle. Confused? Contact us and we’ll dial in a ride to suit you.
Overall, the terrain can tend to be on the sandy side in sections (especially in the summer), so this is a great ride for fat bikes or 29+ bikes. You can do it on a regular mountain bike, but be prepared for some sandy hike-a-bike sections.
- Ride Type: Loop
- Difficulty: Non-Technical, moderate to strenuous climbing with a couple short, steep spots
- Time of Year: Spring, Summer, Fall (possible in Winter/depending on snow pack)
- Terrain/Conditions: Mostly smooth double-track and fire road with some soft & sandy sections.
- Access: From the junction of Highway 203 and Highway 395, go east on the 203 (away from Mammoth) towards the geothermal plant. Make a right turn on Old Highway 395. After approximately 0.2 miles look for a dirt parking lot on your left. Park here, this is where the ride starts.
- Length: 10.0 miles
- Approx. Time: 1.5 – 2.5 hours
- Lowest Elevation: 7,106′
- Highest Elevation: 7,924′
- Total Elevation Gain: 1,449′
- Bike Recommendation: Fat Bike or 29+ because of the sandy sections, but any mountain bike will suffice.
- GPX file: Available by contacting us
Turn by Turn (in miles):
Since this route isn’t signed, and it makes its way through a spaghetti network of OHV trails, we’re not going to post turn by turn directions. We’d prefer you contact us for the gpx track/ map, which will set you up for success.
Casa Diablo Overlook Ride – Map.
Casa Diablo Overlook Ride – Elevation Profile.
Descending towards Mt. Morrison and the Sierra Crest.
Casa Diablo Weather Station
View from the overlook to Mammoth Mountain and the geothermal plant below.
Views towards Crowley Lake and the airport from the couch.
I love this couch that someone strategically placed up here.
Looking back from the couch towards the radio towers.