We Almost Told You to Swim at Hot Creek — Here's the Real Mammoth Lakes Combo Trip
Our own data flagged the area around Mammoth Mt RV Park as a top-tier free camping combo trip — a waterfall, a hot spring, a swimming hole, and a cave, all within about 7 miles. When we actually checked it, one of those four turned out to be something we can’t recommend as written, and it’s the kind of catch worth showing our work on rather than quietly fixing behind the scenes.
The Problem: Hot Creek Isn’t a Swimming Spot Anymore
Hot Creek Geologic Site is genuinely famous, and the data isn’t wrong that it’s there — it’s just wrong about what you can do there now. Hot Creek has been under an active Inyo National Forest closure order since December 31, 2024, running through December 31, 2026, prohibiting all water contact. This isn’t a soft recommendation — it’s an enforced closure, because the geothermal activity underneath the creek can spike water temperature to scalding within seconds, without warning, from earthquake-triggered geyser activity. The site has a documented history of serious injuries going back decades.
You can still visit. It’s a legitimate, free, fenced overlook where you can watch real fumaroles and small geysers from a safe distance — just don’t go in the water, and don’t let a trip-planning site that hasn’t checked recently tell you otherwise.
What’s Actually Good Here
Twin Falls
Twin Falls — a real, easy, 250-foot year-round waterfall dropping from Lake Mamie into Lower Twin Lakes. You can see it from Lake Mary Road with a parking area right there, from the bridges crossing Twin Lakes, or hike the short 0.4-mile trail to the overlook for a closer look. Straightforwardly one of the better low-effort waterfall stops in the Eastern Sierra.
A Primitive Hot Spring — With a Caveat
Our data flags a hot spring roughly 4.6 miles from the camping anchor, in the general direction of the Long Valley / Old Mammoth Road area. That corridor genuinely has several real, free, primitive soaking pools — Whitmore, Shepherd, Wild Willy’s, and a few smaller unnamed tubs are all in that general stretch. What we can’t do responsibly is confirm the exact named pool at those specific coordinates, because these are primitive geothermal pools on undeveloped land — they shift, dry up seasonally, and access details change more often than a formal trailhead would. Treat this as “there’s real primitive soaking in this area, confirm current conditions before you go,” not a guaranteed stop.
Hole in the Wall — Real, But Not a Casual Stop
Hole in the Wall is a genuine lava tube forming a natural rock arch on the southeast side of Mammoth Mountain — and it’s also a double-black-diamond backcountry ski descent in winter, reached by riding the Mammoth Mountain gondola up and traversing a ridge through real avalanche terrain. In summer it’s a serious scramble, not a maintained trail. This is not “stop by this cave on your way to the campsite.” If you’re an experienced backcountry skier or a confident off-trail hiker, it’s a legitimately cool feature. If you’re not, skip it and don’t feel like you missed a highlight — the waterfall and the camping are worth the trip on their own.
Sherwin Lakes Trailhead
The hiking connection our data flagged — a real trailhead into the Sherwin Lakes basin, less than 2 miles from the RV park, if you want an actual maintained trail instead of the technical scramble above.
The Honest Version of This Trip
Camp near Mammoth Mt RV Park, hike or drive to Twin Falls for the easy, reliable payoff, and treat Hot Creek as a look-don’t-touch geology stop rather than a soak. If you’re set up for it, check current conditions on the Old Mammoth Road hot springs before counting on one specific pool. Save Hole in the Wall for a trip where that’s the actual objective, with the right gear and experience for it — not a bonus stop on a relaxed camping weekend.
This one’s a good reminder that a proximity match in a database and an actual safe, legal recommendation aren’t always the same thing. The clustering found something real. It took an actual look to know which parts of it to trust.
Explore this area and hundreds of other real combinations on the Trek4Free map.
