Most of the lava you can reach on public land is old beyond any useful sense of the word. The basalt under a Western dirt road usually cooled millions of years ago and has weathered to brown rock and soil, indistinguishable at a glance from any other stone. in a few places across the United States, however, the rock is young enough to still be black and sharp, barely started on the long job of turning back into dirt, and in a handful of them a paved or graded road runs straight across it.
Geologists draw the young line at the Holocene, the roughly 11,000 years since the last ice age. Every route below crosses volcanic ground younger than that, and most of it younger than the pyramids of Egypt. None of them needs a built rig. Four are paved roads any vehicle can drive, one is a graded-gravel loop, one is an OHV network for full-size 4WDs, and the last is an open cinder field.
Craters of the Moon Loop Drive, Idaho
Photo: NPS / David Hunter
This is the one to build a trip around. A seven-mile paved loop runs off US-20/26/93 near Arco, Idaho, into the largest young lava field in the Lower 48, a black sea of aa flows and cinder cones spread along the Great Rift. The U.S. Geological Survey counts eight separate eruptive periods here between about 15,000 and 2,000 years ago. The youngest flows are roughly 2,000 years old, and because the field's quiet intervals have averaged about that long, the USGS figures another eruption is likely within the next thousand years.
The loop has seven stops, most with a short paved walk. Climb the bare cinder cone at Inferno Cone for a view down the whole rift, look into the vents at the Spatter Cones, and drop into a lava tube in the Caves Area, which needs a free permit from the visitor center. The road is open to cars from about mid-April through mid-November and closes under snow the rest of the year, when the Park Service grooms it for cross-country skiing. There is no fuel or water on the loop, so fill up in Arco first.
McKenzie Pass, Oregon
Photo: U.S. Forest Service, Pacific Northwest Region
OR-242 climbs to 5,324 feet at McKenzie Pass and crosses an open lava sea in the central Oregon Cascades. The flows came off Belknap and Yapoah craters between about 1,500 and 2,900 years ago, according to the USGS, and the Dee Wright Observatory at the summit is built of the same black basalt it sits on. The 82-mile loop combines OR-242 with OR-126 and US-20, and for a few miles at the top the road runs through nothing but fresh rock.
OR-242 is snowed in most of the year and usually reopens in late June or early July, so this is a July-through-October drive. The pass road has a 35-foot length limit, which pushes trailers and larger RVs onto US-20 over Santiam Pass instead.
Newberry Auto Tour, Oregon
Photo: Chris Light (CC BY-SA 4.0, via Wikimedia Commons)
Forest Road 21 leaves US-97 south of Bend and climbs 17 paved miles into the Newberry Caldera, past Paulina and East Lakes and up to the Big Obsidian Flow. At roughly 1,300 years old, the flow is the youngest lava in Oregon, a mile-square pile of black volcanic glass. The car drives the Holocene caldera floor; a short interpretive trail takes you out onto the obsidian itself.
The main road is usually clear from June into October and needs a Northwest Forest Pass or a Newberry day-use pass. A four-mile gravel spur climbs to Paulina Peak at 7,985 feet for a look down into the whole caldera.
Diamond Craters, Oregon
Photo: Greg Shine, Bureau of Land Management (public domain, via Wikimedia Commons)
The least-known route on this list is a 13-mile graded-gravel loop across a BLM Outstanding Natural Area in Harney County, about 40 miles southeast of Burns. Peer-reviewed dating puts the Diamond Craters pahoehoe field at roughly 7,300 to 7,800 years old, and in a small area it packs in cinder cones, maars, lava tubes, and spatter ramparts, most of them visible from the loop or a short walk off it.
The gravel is fine for a high-clearance vehicle when it is dry and turns slick after rain. Skip the peak of summer, when the black rock bakes; spring and early fall are the better windows.
Windy Ridge, Washington
Photo: U.S. Forest Service, Pacific Northwest Region (public domain, via Wikimedia Commons)
Forest Road 99 is a 16-mile paved spur to the closest road-accessible view of the Mount St. Helens crater, from the east side. The ground here is the youngest on the list by a wide margin. The 1980 eruption stripped these ridges to bare rock only about 46 years ago, and the drive passes ten interpretive stops through the blast zone before it ends above Spirit Lake, still carpeted with a floating raft of trees the eruption knocked flat. What you drive across is blast and pumice deposit rather than a lava flow; the fresh lava is the dacite dome rebuilding inside the crater you look into.
FR 99 is open for the 2026 season and reached only from the north, driving south from Randle. A separate approach, the SR 504 highway to Johnston Ridge on the west side, has been closed by a 2023 landslide and is not expected to reopen until around 2027, which makes Windy Ridge the crater drive that actually works right now.
Markagunt Plateau, Utah
Photo: Ken Lund (CC BY-SA 2.0, via Wikimedia Commons)
This route is the exception, the only one that needs an actual off-road vehicle. The Markagunt Plateau OHV network runs 82 miles across the high country of Dixie National Forest between Cedar City and Panguitch, at 7,500 to over 10,000 feet, and crosses the young basalt flows north of Cedar Breaks. The USGS lists the Markagunt volcanic field as Holocene, with the youngest flows near Panguitch Lake dated to roughly 1,000 years ago.
Most of the network is open to full-size 4WDs, though a two-mile segment near Yankee Meadows is limited to vehicles 62 inches wide or less. It is a summer route, snow-free from about June through October.
Cinder Hills, Arizona
Photo:
The Cinder Hills OHV Area covers 13,500 acres of black cinder just northeast of Flagstaff, next to Sunset Crater. The cinders came out of Sunset Crater around the year 1085, which makes them one of the youngest volcanic deposits in the contiguous states, and the area is open to driving directly on them, on 2-, 3-, and 4-wheel vehicles across open cinder and a network of designated routes. Sunset Crater Volcano National Monument itself is off-limits to vehicles, so the OHV area next door is where the riding is legal.
Bring water and sun cover; the field sits at 7,000 feet with little shade, and the dark ground holds heat. The eruption that laid it down was recent enough that the Sinagua people farming the land below would have watched it happen.