Mount St. Helena

Mount Diablo and Napa Valley from Mount St. Helena

10.5 miles round trip, 2100 feet elevation gain
Difficulty: Moderate
Access: Windy paved road to trailhead, no fee required

Multi-peaked, 4341-foot Mount St. Helena can be seen from most corners of California's Napa and Sonoma Valleys, so it's only natural that the views from the summit also encompass much of California's most famous wine-producing region. The mountain is the tallest point visible from San Francisco Bay; on a clear day, not only can you see back to the Bay but the view may encompass Mount Diablo, Lassen Peak, and the Sierras as well. Such great views and proximity to the Bay Area and the Napa wineries means that Mount St. Helena is a well-loved trail, with plenty of hikers following the fire road that winds to North Peak, its highest point. The views justify the crowds though; even with plenty of company, this is still an enjoyable and scenic hike an hour and a half out of San Francisco. This steadily ascending hike, which lies in Robert Louis Stevenson State Park, also provides an opportunity to visit the site where the famous author once honeymooned.

Mount St. Helena from Calistoga

I hiked Mount St. Helena on a clear May day. From the San Francisco Bay Area, I took US 101 north to Santa Rosa, leaving the freeway at exit 488B for Highway 12. I followed Highway 12 until the freeway ended and then turned left onto Farmers Lane, which I followed north through town for a mile before turning right onto 4th St. I followed 4th St east 2.5 miles to the junction with Calistoga Road; here, I took turned left and followed Calistoga Road over a low mountain range to Calistoga; at the junction with Highway 128, I turned left and circled to the north around the town by taking Tubbs Lane to reach Highway 29. I turned left onto Highway 29 and then followed it north through a series of intense turns and switchbacks until I reached the trailhead for Robert Louis Stevenson State Park. The trailhead was marked by gravel parking areas on either side of Highway 29 at the top of the pass over the Mayacamas Range. I parked on the west side of the road here, as the Mount St. Helena Trail starts from that side. It's also possible to reach the trailhead by taking Highway 29 north from Vallejo through Napa Valley and Calistoga.

From the trailhead, a path led past a grassy flat clearing with a picnic table and then began a steady ascent through the forest. This first mile of the hike connects the trailhead parking lot with the fire road running to the summit and it was the only singletrack portion of trail in the hike. The trail switchbacked as it ascended through forests of oak and madrone, gaining elevation constantly but at a reasonable grade. After four-fifths of a mile of uphill, the trail made a sharp right turn into a shaded gully. Here I found a stone monument dedicated to Robert Louis Stevenson, the Scottish novelist who wrote Treasure Island and Dr. Jekyll and Mr. Hyde. Stevenson and his wife Fanny honeymooned in a cabin at this site in 1880, an experience that inspired Stevenson to write The Silverado Squatters. The cabin is gone today: all that remains is a small flattened clearing.

Robert Louis Stevenson Monument

After passing the Stevenson Monument, the trail made two quick switchbacks to gain the top of a small ridge. This stretch was the rockiest part of the hike: the trail along the ridge was especially rocky and uneven compared to the fairly smooth trails utilized along the rest of the hike.

A mile after leaving the trailhead, I came to an intersection with the fire road leading to the communications towers spread out among the summits of Mount St. Helena. I turned left here and followed the fire road uphill. Be sure to remember this junction on the way back, as it's easy to miss the sign for the trail back down and continue down the fire road.

The fire road quickly took me from the green, forested eastern slopes of the mountain out onto the charred, fire-scarred southern slopes of Mount St. Helena. The open slopes littered with burnt trees delivered the first views of the hike: I could see south down the length of Napa Valley. The forested Sonoma and Mayacamas Mountains bounded the vineyard-filled valley on either side and the twin peaks of Mount Diablo rose above the valley in the distance.

Napa Valley view, Mount Diablo in the distance

Nearby, there was a good view of the Palisades and Table Rock, a collection of columnar basalt formations in the eastern portion of Robert Louis Stevenson State Park. Views of these odd rock formations improved as I continued along the fire road, which ascended at a constant but gentle grade as it made a number of long switchbacks on the mountain's southeast slopes.

Table Rock and the Palisades

The higher that the trail ascended, the better the views were. Soon, I could see neighboring Sonoma Valley and the Pacific Ocean beyond that. The distinctive peak of Mount Tam was also distinguishable, although I could not yet see the water of San Francisco Bay or the city skyline.

Sonoma Valley and the Pacific Ocean

The massive cliffs of Mount St. Helena's southern aspects towered above the trail. The peak is made of uplifted volcanic rock from the Clear Lake Volcanic Field, a large geologically active area just to the north. Eruptions from the Clear Lake Volcanic Field laid down lava flows and pyroclastic flows that today form Mount St. Helena's impressive cliffs. This volcanism is also responsible for the many volcano-related features in northern Napa Valley, including the Petrified Forest on the way to Calistoga and Old Faithful of California, a rare geyser in Calistoga.

Mount St. Helena trail

The fire road switchbacked on the southeastern slopes of the mountain for two miles, yielding ever better views of the Palisades, Napa Valley, Mount Diablo, and the ocean before making a turn to the north. Here, the trail left behind the earlier views and returned to a more forested setting. The trail continued to ascend gently as it cut across the east side of the mountain. Occasionally, there were views to the east of the Vaca Mountains nestling Lake Berryessa.

After 3.5 miles of hiking from the trailhead, the fire road came to the saddle between the South and Southeast Peaks. A branching road led to the summit of the South Peak, which was topped with communications towers; I continued straight in the direction of East Peak, which had communications equipment of its own on its summit. Here, the trail reentered the burn area. The trail dropped slightly to reach a saddle between the Southeast and East Peaks before beginning a steady ascent and wrapping around the East Peak.

Here, the trail passed through swaths of terrain that were denuded. In 2017, the western and southern slopes of Mount St. Helena were burned by the Tubbs Fire, one of the worst wildfires in California history. In addition to burning half of Mount St. Helena, the Tubbs Fire destroyed vast swaths of Napa and Sonoma Valley. Most notably, the fire advanced south from Calistoga to Santa Rosa in a matter of four hours, sweeping into the city of Santa Rosa and setting hundreds of houses ablaze after jumping over US 101. About five percent of residences in Santa Rosa burned during the fire, making this one of the deadlier and more damaging fires in recent California history.

Fire-ravaged, transmission tower-topped peaks of Mount St. Helena

Views to the east were excellent as I ascended up the side of the East Peak. Snowy Lassen Peak rose above the forested plateaus marking the junction of the Sierra Nevada and the Cascades on the horizon. On very clear days, it's said that the view from Mount St. Helena extends as far as Mount Shasta, over 190 miles to the north.

Mount St. Helena cliffs and Lassen Peak

More and more of Lake Berryessa became visible to the east. I also spotted smoke from a small wildfire, a reminder that the landscape in this part of California has been indelibly reshaped by fire in the past few years.

Fire burning near Lake Berryessa

The trail wrapped around East Peak and began heading west, passing through a saddle between East Peak and North Peak before beginning the final climb to the summit of North Peak. On this final ascent, views opened back up to the south and San Francisco Bay finally came into view. The Peninsula was surrounded by the Bay on one side and the Pacific Ocean on the other; however, the view to the south was a bit too hazy to see the San Francisco skyline. A last uphill push brought me to the broad summit area, with a gravel lot and communications towers at the center of the summit and a row of columnar basalt providing views to the north.

Mount Tam, the Peninsula, and San Francisco Bay from the summit of Mount St. Helena

From this basalt summit outcrop, I savored the views to the north. The Mayacamas Range continued stretching to the north: the next major peak was Cobb Mountain, a volcano of the Clear Lake Volanic Field. Beyond Cobb Mountain was Mount Konocti, another volcano on the shore of Clear Lake; Clear Lake itself was not visible from Mount St. Helena. Even farther in the distance was 7050 foot-tall Snow Mountain, one of the first higher peaks in the Coast Ranges north of the Bay Area. Cobb Mountain and the Sonoma Mountains to the west were brown, having been devastated by the 2017 Tubbs Fire as well. The fires of 2017 affected The Geyers geothermal field on Cobb Mountain, which can be seen from the summit of Mount St. Helena. A large building on the slopes of Cobb Mountain with many steam towers is part of The Geysers, a geothermal project that harnesses the energy of the Clear Lake Volcanic Field; this is the largest geothermal energy project in the world and renewably provides a majority of the electricity needed along the California Pacific Coast north of the Golden Gate.

Columnar basalt at Mount St. Helena

Cobb Mountain, Mount Konocti, and Snow Mountain from Mount St. Helena

I sat at the summit and enjoyed the views. On a weekday, there were only a handful of other hikers at the summit, but this hike's excellent views draw plenty of hikers on weekends. If you decide to come, spring is a good time while the hills are green and the weather isn't too hot yet. Even though the hike is never very steep and is thus not terribly difficult, be sure to bring plenty of water as the fire road is constantly in the sun and the mountain can become quite hot on spring and summer afternoons.