California’s best hot springs all come from the same supervolcano, and one of them isn’t safe to swim in anymore
Every hot spring between Mammoth Lakes and Bridgeport comes from the same place. About 760,000 years ago, a supervolcano now called the Long Valley Caldera erupted roughly 150 cubic miles of magma — somewhere around 500 times what Mount St. Helens put out in 1980. The blast left behind a crater eleven miles wide, and the magma chamber underneath never fully cooled.
That’s why this stretch of Highway 395 leaks hot water at nearly every turn. It’s also why one of the area’s most popular soaking spots doesn’t let you in the water anymore.
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The hot spring you can look at but not touch
Hot Creek Geologic Site used to be the easy option — a roped-off swimming hole a few minutes off 395, with a view of the creek’s bubbling “Cauldron.” Since 1998, at least 14 people have been badly burned or killed there when calm-looking water suddenly surged hot.
The Forest Service closed it to swimming in 2006, and a standing closure order keeps it that way through the end of this year. You can still walk down and watch it steam — you just can’t get in, and nobody’s promising that changes.
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Wild Willy’s is the one to actually get in
We showed up at Wild Willy’s at sunrise on a June morning and it was already half full — turns out sunrise is the quiet shift here, which tells you everything about the rest of the day. A boardwalk drops you down to the pools in under a quarter mile, easy enough to do before coffee.
The water runs 95 to 105°F depending on which pool you pick, cooled from a 120°F source higher up. It’s free, it sits on public land, and there’s one larger pool plus a few smaller ones if you want space from the crowd. Go at sunrise — it’s not close.
Travertine Hot Springs looks like it doesn’t belong here
South of Bridgeport, Travertine swaps the boardwalk for raw orange-and-white mineral terraces that look more like Yellowstone than the Eastern Sierra. It’s a five-minute walk from a BLM parking area, completely free, and open all year.
Temperatures swing hard between pools — the source hits 180°F, but most of the soaking pools land somewhere between 90 and 125°F — so test before you settle in.
Buckeye Hot Springs, if you don’t mind a scramble
Buckeye sits inside Humboldt-Toiyabe National Forest, about ten miles outside Bridgeport, where three spring-fed pools line the bank of Buckeye Creek. Reaching the creek-level pools means a rough 150- to 300-foot descent — steep enough that it’s not a casual stroll.
It’s free, undeveloped, and the payoff is soaking in hot mineral water with a cold creek running right next to it. Overheat and you’ve got somewhere to cool off without leaving the spot.
Keough’s, if you’d rather skip the hike entirely
Keough’s Hot Springs, just outside Bishop, has run as a resort since 1919 — the same two pools locals have soaked in for over a century. The big pool holds at 88 to 90°F and the smaller hot pool stays at 104°F, both year-round, no hiking required.
It’s not free — a day pass runs $12 for adults — but you get a snack bar, picnic tables, and pools that don’t depend on the weather cooperating.
Four spots, one supervolcano, four completely different ways to get wet. Sunrise boardwalk, mineral terraces, a creekside scramble, or a pool that’s been running since 1919 — which one are you picking first?
Trip tips: grab a rental car to get out here, lock in your hotel before the good rooms are gone, or skip both and book a camper van instead.
Rules and fees change — always confirm current requirements before you go.
