The Only Volcano on Route 66

Midway between Barstow and Needles, in the empty heart of the eastern Mojave Desert, something appears on the southern horizon that stops travelers cold: a dark, perfectly symmetrical cone rising 250 feet above the flat desert floor, surrounded by miles of black basalt lava fields that look as if they cooled sometime last week. This is Amboy Crater — a dormant cinder cone volcano that is the most dramatically geological stop on Historic U.S. Route 66, a National Natural Landmark designated in 1973, and the only volcano along the entire 2,448-mile length of the Mother Road.

The crater sits 1.5 miles south of Route 66 (the National Trails Highway) near the near-ghost town of Amboy, California, in San Bernardino County — reachable via a paved access road that puts travelers inside one of the most otherworldly landscapes in the American Southwest within minutes of leaving the highway. The Bureau of Land Management (BLM) manages the site as part of the 1.6-million-acre Mojave Trails National Monument. There is no entrance fee. The crater is free to visit, free to hike, and — in the desert’s cold, dark, moonless nights — one of the finest stargazing locations in southern California.

For generations of Route 66 travelers from the 1920s through the 1960s, Amboy Crater was one of the most memorable stops on the California leg of the Mother Road. Families pulled off the highway, climbed a real volcano in the middle of the Mojave Desert, and drove on to the coast. When Interstate 40 opened in 1973 and redirected traffic away from the old Route 66 alignment, the crater — like the town of Amboy itself — grew quieter. But the revival of Route 66 tourism has brought visitors back, and Amboy Crater has become, once again, exactly what it was in the highway’s golden years: the most extraordinary natural landmark on the California desert road.

Where Is Amboy Crater?

Amboy Crater is located approximately 2.5 miles southwest of the town of Amboy on Crater Road, which turns south off the National Trails Highway (Historic Route 66) in the eastern Mojave Desert. The trailhead address is: Crater Road and Route 66, Amboy, CA 92304. GPS coordinates: 34.5572°N, 115.7814°W.

The crater is situated roughly equidistant between Barstow and Needles — approximately 66 miles from each — on the old Route 66 alignment through the Mojave. To reach it:

From Barstow: Take I-40 east to Exit 50 (Crucero Road). Turn right on Crucero Road, then immediately left onto Route 66 (National Trails Highway). Follow Route 66 east for approximately 26 miles to Crater Road. Turn right (south) and follow the paved access road to the parking area.

From Needles: Take I-40 west approximately 65 miles to Kelbaker Road (Exit 78). Exit south on Kelbaker Road and drive approximately 10 miles to the National Trails Highway (Route 66). Turn left (west) and drive approximately 8 miles to Crater Road. Turn left (south) to the parking area.

From Twentynine Palms: Take Amboy Road north from Twentynine Palms through the desert approximately 40 miles to Amboy on Route 66. Turn right on Route 66, then left on Crater Road. Plan for a half-day visit with the drive time.

The crater is visible from Route 66 and from the parking area. The Bullion Mountains rise to the west, the Bristol Mountains stand to the northeast, and the immense Bristol Dry Lake — a salt flat that is one of the largest in the Mojave — fills the eastern horizon from the crater’s rim.

The Geology: A 79,000-Year-Old Volcano in One of the Youngest Lava Fields in America

What Is a Cinder Cone Volcano?

Amboy Crater is a cinder cone — the simplest and most visually recognizable form of volcano. A cinder cone forms when gas-charged basaltic lava is ejected violently from a single vent, cooling in the air to form solid cinders (also called scoria) that fall back around the vent and accumulate into a cone-shaped hill. The process produces a nearly symmetrical form: the classic volcanic silhouette that has represented “volcano” in the human imagination for thousands of years. Amboy Crater is one of the most perfect examples of this symmetry in the American West — the BLM describes it as“an almost perfectly symmetrical volcanic cinder cone.”

Formation and Age

The cinder cone itself is estimated to be approximately 79,000 years old (plus or minus 5,000 years), formed during the Pleistocene geological period in layers of mostly vesicular pāhoehoe lava — the smooth, ropy variety of basalt that forms when lava cools while still in motion. The crater sits at 944 feet above sea level, rising 250 feet above the surrounding lava fields, and its rim is 1,500 feet in diameter — wide enough to walk the circumference comfortably, with views in every direction across the desert floor.

Critically, the crater’s most recent eruption was approximately 10,000 years ago — within the period of human habitation in the region — making the lava fields that surround it among the youngest volcanic landscapes in the United States. The 10,000-year-old flow is visible from the air as a distinctly darker lava surface overlying the older flows; from the ground, the lava field’s youth is apparent in how sharp and uneroded the rocks remain — basalt that has not had time to be softened by millennia of weathering.

The Lava Field: 24 Square Miles of Volcanic Geology

The 24-square-mile lava field that surrounds Amboy Crater is the product of successive eruptions over tens of thousands of years, each adding new material to the landscape. A breach on the western side of the crater is where the most significant lava outflow occurred — the point at which the cone’s wall gave way under the pressure of a lava lake inside the crater, releasing basaltic flows that spread across the desert floor. This breach is the entry point used by the hiking trail today.

The lava field contains a variety of volcanic formations that reward attentive exploration. Vesicular basalt — porous rock where gas bubbles were trapped in cooling lava — is the most common surface material, its honeycombed texture visible throughout the trail. Lava tubes (now collapsed into trenches and depressions), spatter cones (small secondary cones formed by lava fountaining), pressure ridges, and lava bombs (rounded masses of lava that cooled during flight) are all present in the field around the crater. Inside the crater itself, two solidified lava lakes — now flat, clay-covered surfaces resembling miniature dry lakes — occupy the spaces behind lava dams formed during earlier eruptions.

Tectonic Activity: The 1999 Hector Mine Earthquake

The region around Amboy Crater remains tectonically active. On October 16, 1999, the Hector Mine earthquake — a magnitude 7.1 event — struck with its epicenter just miles from the crater, a reminder that the eastern Mojave’s volcanic geology reflects ongoing tectonic processes rather than a purely ancient history. The earthquake caused no major damage to the crater itself but was felt across a wide area of southern California and underscored the geological dynamism of the landscape that Amboy Crater represents.

Amboy Crater and Route 66: The Only Volcano on the Mother Road

When U.S. Route 66 was commissioned in November 1926 along the National Old Trails Highway alignment, it gave millions of cross-country travelers direct access to the Mojave Desert’s volcanic landscape. The crater had been geologically present for millennia, of course, but it was Route 66 that made it a stop on the American road trip itinerary — a landmark that travelers could add to their list of experiences alongside the Grand Canyon, the California coast, and the Mississippi River.

Amboy Crater earned a special distinction among Route 66 natural attractions: it was the only dead volcano along the entire route. (A stretch of Route 66 in New Mexico passes near volcanic terrain, but Amboy Crater was the most accessible and dramatically visible.) For generations of Route 66 travelers from the 1920s through the 1960s, this was a genuinely unique selling proposition: where else on a cross-country drive could you pull off the highway, walk across a lava field, and stand inside a real cinder cone volcano? The crater became a staple of the California leg — a stop that travelers specifically planned for and that delivered an experience unavailable anywhere else on the Mother Road.

The crater’s role as a Route 66 attraction collapsed when Interstate 40 opened in 1973, diverting traffic away from the old National Trails Highway alignment through Amboy. With the through traffic gone, the crater saw sharply fewer visitors for two decades. The revival of Route 66 heritage tourism — accelerated by the designation of Mojave Trails National Monument in 2016 and the approaching Route 66 Centennial in 2026 — has returned Amboy Crater to its place as one of the most visited stops on California’s Route 66 corridor. The crater is now the most visited destination within Mojave Trails National Monument, receiving visitors from around the world who come specifically to combine the Route 66 experience with the geological spectacle.

Hiking Amboy Crater: The Trail Guide

Trail Overview

The Amboy Crater Trail is a 3-mile round trip hike that crosses the lava field from the parking area to the base of the crater, enters through the western breach, and ascends to the rim via the Western Cone Trail — the route recommended by the BLM as the safest and most established path to the summit. The total elevation gain is approximately 250 feet — modest in absolute terms, but demanding in conditions: the lava field surface is uneven and sharp underfoot, the desert provides no shade, and the crater’s loose cinder surface requires careful footing on the final ascent.

In 2020, Amboy Crater Trail was added to the National Recreation Trails System — a designation honoring trails of outstanding recreational quality and public access. It is one of the best-regarded hikes in the eastern Mojave Desert.

The Trail Step by Step

Trailhead to Lava Field (0–0.5 miles): The trail departs from the parking area on a wide, clearly marked path. An ADA-accessible observation platform near the trailhead provides a shaded overview of the crater and lava field — a useful orientation point before beginning the hike, and the primary viewing option for visitors who cannot do the full trail. The trail narrows as it enters the lava field, transitioning from packed desert sand to the black basalt surface of the ancient flows.

Across the Lava Field (0.5–1.1 miles): The bulk of the outbound hike crosses the lava field itself, winding through twisted basalt formations toward the base of the cone. Rest benches with limited shade are positioned along the route at intervals, providing recovery points and reflecting the BLM’s recognition that desert heat and the mentally demanding character of hiking on black lava require more rest opportunities than equivalent distances on softer terrain. The trail is not always clearly visible across the lava surface; trail markers provide navigation guidance where the path is less obvious, and the direction of travel — toward the crater — is always clear.

The Western Breach Entry (1.1–1.3 miles): The trail approaches the crater from the west, entering through the breach — the gap in the crater wall where lava once poured out across the desert. Passing through the breach is the hike’s most dramatic moment: the scale of the opening and the black interior of the cone become suddenly visible, and the transition from desert floor to volcanic interior happens in a few steps. The BLM specifically recommends the Western Cone Trail through this breach as the safest ascent route; an older, eroded scar on the cone’s face should not be used.

The Rim Ascent (1.3–1.5 miles): From the breach, the trail switchbacks up the interior wall of the cone to the rim. This is the steepest and most physically demanding section: loose cinder underfoot, significant exposure to sun and wind, and the need for careful footwork on the final approach to the top. The BLM recommends sturdy closed-toe shoes specifically for this section; casual sandals or flip-flops are hazardous on the loose cinder surface. Trekking poles are helpful for balance, particularly for hikers with any concern about heights or exposed terrain.

The Rim (1.5 miles): The view from the 1,500-foot-wide rim is one of the finest panoramas available from any trail in the California desert. To the east, the Bristol Dry Lake — one of the Mojave’s largest salt flats — spreads across the desert floor. To the west, the 26-mile lava flow is visible as a dark band across the lighter desert. The Bullion Mountains define the western horizon, the Bristol Mountains rise to the northeast, and the Marble Mountains are visible to the south. Route 66 — the National Trails Highway — is visible in the distance to the north, and on clear days the BNSF freight trains passing through Amboy appear as small objects moving across the enormous landscape. The caldera below — the interior of the crater — is accessible by a separate path from the breach, providing an additional perspective from within the volcano rather than above it.

Trail Difficulty and Safety

The BLM classifies the trail as moderately difficult due to the uneven lava surface, the steep final ascent, and the extreme desert conditions. The single most important safety factor at Amboy Crater is temperature. Summer temperatures at the crater routinely reach 110°F to 120°F, and the black lava surface absorbs and radiates additional heat, making the trail significantly hotter than the air temperature. People have died at Amboy Crater due to heat and dehydration. The trail is not recommended in summer (late May through September) under any circumstances except at sunrise with full water preparation. The optimal hiking season is October through April, with October–November and February–April being the most comfortable months.

Safety checklist for every visit:

Water: Bring a minimum of 2 liters per person for the full hike. There is no water at the trailhead or along the trail.

Sun protection: Hat, sunscreen, and sunglasses are essential. The lava field is fully exposed with no shade except at the rest benches.

Footwear: Sturdy closed-toe hiking shoes or trail runners are required. The lava surface is sharp and irregular.

Wildlife: Watch for rattlesnakes, particularly in shaded areas around rest benches and rock formations. Also be alert for the BLM’s specific warning about old military ordnance in the area, a residue of WWII-era training exercises in the Mojave.

Tell someone your plan: Cell service is minimal to nonexistent in Amboy. Inform someone of your itinerary before departing. The nearest significant services are in Twentynine Palms (about 40 miles south) or Barstow (about 66 miles west).

Facilities at the Amboy Crater Trailhead

The BLM has developed a well-maintained day-use area at the Amboy Crater trailhead that includes:

Parking: A paved lot with spaces for standard vehicles and RVs. A separate group parking area is available for organized visits. No fee.

ADA-Accessible Observation Platform: A shaded ramada approximately 250 feet from the parking area providing crater views for visitors who cannot complete the trail.

Picnic Tables: Both shaded and unshaded picnic tables are available, providing a welcome rest stop in an area with no commercial food services.

Restrooms: Vault toilets are available and are described by visitors as consistently clean and well-maintained — a notable accomplishment given the remote location.

Interpretive Kiosk: Trail information, geological context, desert safety tips, and a map of the route are provided at the trailhead.

Beyond the Hike: Other Reasons to Visit Amboy Crater

Stargazing and Astrophotography

Amboy Crater has become one of the premier stargazing and astrophotography destinations in southern California. The combination of extreme light pollution absence (the nearest city of any size is 66 miles away), high desert elevation, typically clear skies, and the dramatic silhouette of the cinder cone against the night sky creates conditions that attract astrophotographers from across the region. The Milky Way is described by visitors as appearing “almost three-dimensional” on clear moonless nights.

Camping at the overflow parking area (not the main day-use lot, which does not permit overnight stays) is free, allowing stargazers to arrive in the evening, photograph the night sky, and hike the crater at sunrise — the optimal combination for both experiences and the most efficient way to beat the desert heat. Dispersed camping is also permitted in the surrounding Mojave Trails National Monument, subject to standard BLM Leave No Trace regulations. The nearby Afton Canyon Campground provides a developed camping option for those preferring established facilities.

Spring Wildflowers

In years of adequate winter rainfall, the lava fields around Amboy Crater produce spring wildflower displays that are genuinely extraordinary given the harshness of the environment. Fields of desert sunflower, sand verbena, desert primrose, and Ajo lilies bloom against the black basalt, creating color contrasts that seem almost impossible in a landscape so dominated by volcanic rock. The bloom typically begins as early as late January and peaks in February and March depending on precipitation. The BLM’s trail managers have documented particularly spectacular blooms around the trail’s rest stations, where some soil accumulation supports plant growth.

Wildlife

The lava field supports a surprisingly diverse reptile community adapted to the harsh basalt environment. The desert iguana, chuckwalla, zebra-tailed lizard, and various whiptail lizard species are commonly observed along the trail. The blowing sand in the lava field creates habitat for insects and small invertebrates that support these reptile populations. Rattlesnakes are present and should be given wide berth, particularly in shaded areas where they shelter from the sun. Bird activity is limited by the exposed character of the lava field, but raptors use the thermal columns above the crater for hunting and soaring.

Photography

Amboy Crater is one of the most photogenic natural landscapes on California’s Route 66 corridor. The golden light at sunrise and sunset transforms the black lava’s surface texture into a complex play of shadows and highlights, producing images of extraordinary depth. The crater’s rim provides the best vantage point for wide-angle shots incorporating the Bristol Dry Lake, the surrounding mountain ranges, and the desert highway in the middle distance. Macro photography along the trail reveals the detailed textures of vesicular basalt, lava bombs, and desert plants growing in the cracks of the lava field.

Amboy Crater on Film and Television

The crater’s dramatic profile and remote desert setting have attracted filmmakers since the mid-20th century. Its most significant appearance was in the 1959 science fiction film Journey to the Center of the Earth starring James Mason and Pat Boone — a production for which the crater served as the exterior volcanic landscape. Matte paintings were used to alter the cone’s shape and composite it into the landscape of Iceland, and fires were set inside the crater to simulate a volcanic eruption. The geological authenticity of the real cinder cone gave the film’s volcanic sequences a visual credibility that studio sets could not have achieved.

The crater also appeared in the HBO series From the Earth to the Moon, in an episode documenting Apollo 15 astronaut training: the Amboy lava fields were overflown as a stand-in for the volcanic terrain outside Flagstaff, Arizona, that was used for actual NASA lunar geology preparation. The choice reflects how closely Amboy Crater’s geology mirrors lunar volcanic landscapes — a comparison that gives the site additional scientific interest beyond its Route 66 history.

More recently, the Viceland network’s documentary series Abandoned featured Amboy Crater in its Season 1 Route 66 episode, introducing the crater to a new generation of viewers in the context of the broader Route 66 preservation and heritage story.

Amboy Crater and Roy’s Motel and Café: The Complete Amboy Stop

Any visit to Amboy Crater naturally pairs with a stop at Roy’s Motel and Café — the iconic Route 66 landmark located approximately 2 miles north of the crater turnoff on Route 66, in the center of the near-ghost town of Amboy. Roy’s 50-foot Googie neon sign, restored and relit in 2019, is the most photographed landmark on California’s Route 66 corridor; the gas station is operational; and the gift shop and coffee bar serve travelers on the National Trails Highway.

The combination of Roy’s Motel and Café and Amboy Crater makes Amboy one of the most concentrated Route 66 experiences available in the California desert: the Googie architecture and neon of the highway’s mid-century commercial culture, immediately adjacent to the ancient geology that that culture was built across. Plan for a minimum of three to four hours to explore both stops thoroughly — Roy’s for the Route 66 history and photography, the crater for the hike and the views.

Practical Information

Trailhead Address: Crater Road and Route 66 (National Trails Highway), Amboy, CA 92304

GPS Coordinates: 34.5572°N, 115.7814°W

Managing Agency: Bureau of Land Management (BLM), Needles Field Office, 1303 South U.S. Highway 95, Needles, CA 92363. Phone: (760) 326-7000

Admission: Free. No entrance fee.

Trail: 3 miles round trip. Elevation gain 250 feet. Rated moderately difficult.

Facilities: Paved parking for all vehicle sizes including RVs, ADA-accessible observation platform, shaded and unshaded picnic tables, vault toilets, interpretive kiosk.

Camping: No overnight camping in the main day-use parking lot. Free dispersed camping permitted in the overflow lot and on surrounding BLM/Mojave Trails National Monument land. Afton Canyon Campground is a developed option nearby.

Best Season: October through April. Avoid May through September due to extreme heat (110°F–120°F). Best wildflowers late January through March.

Water: No water at the trailhead. Bring a minimum of 2 liters per person. Fill up in Twentynine Palms (approximately 40 miles south via Amboy Road) or Barstow (approximately 66 miles west).

Cell Service: Minimal to nonexistent in Amboy. Download offline maps before departing populated areas. Tell someone your itinerary.

Gas: Roy’s Motel and Café in Amboy (approximately 2 miles north on Route 66) has a functioning gas station, though prices are higher than city rates due to remote location. Fill up before departing Twentynine Palms or Barstow.

Stargazing: New moon weekends provide the best dark sky conditions. The overflow parking area allows overnight stays for astrophotographers.

Nearest Services: Roy’s Motel and Café, Amboy (gas, snacks, water, restrooms). Full services in Twentynine Palms (~40 miles south) or Barstow (~66 miles west).

Nearby Route 66 Highlights Along California’s Desert Corridor

Roy’s Motel and Café, Amboy, California — The most photographed landmark on California’s Route 66, located approximately 2 miles north of the crater turnoff. The restored 50-foot Googie neon sign, operational gas station, coffee shop, and gift shop make Roy’s the essential companion stop to Amboy Crater.

California Route 66 Museum, Victorville — About 90 miles west of Amboy via Route 66 and I-15, the free California Route 66 Museum in Victorville’s Old Town is the Mother Road’s own museum in the Mojave Desert.

Barstow Harvey House — Casa del Desierto — Approximately 66 miles west in Barstow, the restored 1911 Fred Harvey railroad hotel is a National Historic Landmark housing the Route 66 Mother Road Museum and the Western America Railroad Museum. Free admission.

The Wigwam Motel, San Bernardino — About 130 miles west, the iconic Wigwam Motel in San Bernardino has offered teepee-shaped rooms to Route 66 travelers since 1950.

Route 66 in California — Complete Guide — The full overview of California’s 314-mile Route 66 corridor from Needles on the Arizona border through Amboy, Barstow, Victorville, San Bernardino, and Los Angeles to the Santa Monica Pier.

Route 66 Centennial 2026 — The 100th anniversary of Route 66 is November 11, 2026. Amboy Crater, Roy’s Motel, and the California desert corridor are all part of the centennial celebrations.

Route 66 — Complete Guide — The definitive guide to all 2,448 miles of America’s Mother Road, from the Begin sign in Chicago to the End of the Trail at the Santa Monica Pier.