Mount San Jacinto State Park: Round Valley Loop & Hidden Lake

Part two of our San Jacinto summer project: butterscotch-scented pines, a vanishing snowmelt lake, and a wildflower that grows nowhere else on Earth

Hike number two in our summer quest to summit San Jacinto Peak (or at least hike as many trails as we can manage in the San Jacinto State Park), and we’re back at the tramway for the first car up the mountain. Full disclosure: a couple of us needed a quick shot of coffee before we could manage the walk down the ramp. Turns out altitude makes you yawn a lot so if you catch your hiking buddies gaping like sleepy goldfish, blame the thin air. Probably.

Today’s mission: the Round Valley Loop and Hidden Lake. This one takes two permits, a (free) wilderness permit, and a special permit just for Hidden Lake. Only 30 of those Hidden Lake permits are handed out per day, and the trail is only open Friday through Monday, so a little planning goes a long way.

The Round Valley Loop winds through gorgeous pine forest, and every time I come up here from the desert floor I’m struck by how fast the world changes. Leave the cactus and creosote behind, ride ten minutes uphill, and suddenly you’re standing in an alpine forest. In fact, the tramway climbs nearly 6,000 feet (1,790 m) and passes through five life zones, from the Sonoran Desert to the alpine. People love to describe it as driving from Mexico to Canada, except this trip takes just 12 minutes.

As the group’s self-appointed — read: unelected — naturalist, I like to assign everyone two trees to learn each trip. Today’s homework: the Jeffrey Pine and the White Fir. Both are easy to spot. For me. Which makes it very easy to play teacher. 😉

The Jeffrey Pine is the most common pine in these mountains. It grows up to about 90-100 ft (27-30 m) tall, can live up to 500 years, and wears a distinctive red-brown, deeply furrowed bark. But the real party trick is the smell: press your nose into the bark and you’ll catch notes of butterscotch and vanilla. Yes, you will look ridiculous. Yes, it’s worth it. “Stop and smell the tree bark” is now an official trail motto.

The White Fir is the easy one to mistake for a pine, but here’s your insider tip, and it’s the single best way to tell firs from pines: pines hold their needles in little bundles, while firs attach each needle singly, straight to the branch. The White Fir’s are short, soft, and flat, with grey-white bark to match. They reach up to about 70-160 ft (21-49 m) tall and can live up to 300 years. (And yes — technically a fir is not a pine. Consider that your bonus extra credit.)

The other two conifers? Those are on next week’s pop quiz. 😄

We hiked on to the Hidden Lake trail. Hidden Lake is a vernal pool, fed entirely by snowmelt, which means it fills in spring and shrinks through summer until it’s bone dry by late season. Right now it’s still about half full. The reason for that special permit is the Hidden Lake bluecurls, a small purple wildflower found nowhere else on Earth but the edges of this one pool. It spent two decades on the federal endangered species list before recovering enough to be delisted in 2018 — but it’s still carefully protected, which is why visitor numbers are capped.

The lake sits at a beautiful open overlook above the Coachella Valley and the Salton Sea. Today the air was too hazy to catch the Salton Sea, but we lingered anyway, said hello to a few exceptionally handsome sagebrush lizards, and turned back toward the Mountain Station.

Two trees down, one peak to go. Next time, we climb higher. Stay tuned. 👟

The Quick Trail Guide

Location: Mount San Jacinto State Park, at the top of the Palm Springs Aerial Tramway

Getting there: Ride the Tram up from Valley Station. From the Mountain Station, take the paved ramp down to the wilderness area and follow the signs toward Round Valley Loop.

Trail length: ~5-mile (8 km) loop, combining the Round Valley Loop with the Hidden Lake detour

Elevation: Mountain Station 8,516 ft (2,596 m); Hidden Lake ~8,700 ft (2,652 m); roughly 950 ft (290 m) of total gain

Difficulty: Moderate

Permits: Two required — (1) a free wilderness day-use permit, available at the ranger station just past the Mountain Station, and (2) a separate Hidden Lake permit, capped at 30 per day, first come, first served

Hidden Lake access: Friday–Monday only — confirm current rules before you go

Best time of year: Late spring through early fall; go in early summer if you want to catch Hidden Lake still holding water

What to bring: Water, sun protection, a light layer, and sturdy sneakers (obviously)

Trail etiquette: Stay on the marked paths near Hidden Lake — the bluecurls and the fragile pool habitat depend on it

Cost: Tram ticket required (check pstramway.com for current rates); parking fee at Valley Station

Facilities: Restrooms, dining, and gift shops at the Mountain Station