Fort Rock State Natural Area Trailhead

Fort Rock stands about a mile north of the town that shares its name, a near-circle of jagged rock walls on a valley floor so flat that the state park’s own description says it rises “like a desert mirage.” The approach leaves Oregon Highway 31 on Fort Rock Road, runs east past the few buildings of downtown Fort Rock, and turns left for the last half mile to the state natural area. The ground lies in Lake County and is managed by Oregon State Parks.

Accounts of the size vary. The geologist David Sherrod, writing for the Oregon Encyclopedia, gives the cliffs as rising nearly 260 feet, and 350 feet from summit to basin floor when the sloping base is counted. The Fort Rock Valley Historical Society says 325 feet above the plain. Measured rim to rim, Sherrod puts the ring at about 2,300 feet by 1,700 feet, an oblong with an opening to the southeast “much like a distorted horseshoe.” The state park advises that a walk around it shows the rock is “even bigger than it looks.”

Benches above the parking area

The public parking area sits on the south and southeast side, close to the open end of the ring. In the cliffs above it are flat rock benches at about the 4,440-foot level, cut by the waves of Fort Rock Lake. Sherrod writes that their promontories are the most popular hiking destinations on the rock. A trail circles the interior of the crater, whose floor stands 6 to 12 meters above the old lake basin, according to a U.S. Geological Survey field guide. The rock itself is orange-brown lapilli tuff laid down in beds from about a centimeter to a meter thick.

The cliffs are pitted by cavernous weathering, a slow weakening of the rock by mineral salts. The pits now serve as roosts and nest sites for rock pigeons, ravens, and prairie falcons. White-throated swifts nest in the larger cracks, and cliff swallows fix their mud nests under the overhangs. Sherrod notes that public access to the nesting areas is closed during falcon brooding season, February 15 to August 30. Drones are prohibited year round under a state advisory effective February 21, 2026, through August 15, 2028, chiefly to protect the resident nesting eagles and falcons.

Travel Oregon lists the site under stargazing. Visitors who stay past closing to watch the sky must print the state’s Stargazing Permit, fill it out, and leave it on the vehicle dash while parked in the designated day-use area.

Magma, water, and three weeks

Fort Rock is a tuff ring. Rising basaltic magma struck water and exploded, the state historical marker on Highway 31 explains, and the debris fell back around the vent to build the steep walls. Sherrod gives the particulars. The magma, hotter than 2,000°F, flashed the water to steam, either from a pluvial lake or from abundant shallow groundwater. The expanding steam drove surges of wet ash, scoria, and bedrock blocks out from the vent, and the layers hardened into rock that resembles a poorly sorted, coarse sandstone. The vent seems to have wandered a few hundred feet during the eruption, so that the present rim is a composite of smaller rings, each once circular and 1,000 to 1,600 feet across. Judging by its volume and the rates of historic tuff-ring eruptions, the whole formation probably took less than three weeks to build.

Evidence of collapse during the eruption shows most plainly on the west side of the crater. There, beds that dip steeply into the crater lie against older beds that dip outward and were cut off when the vent walls sloughed into the throat.

The sources differ on the age and on how the ring was opened. The National Park Service says Fort Rock formed 10,000 to 12,000 years ago. Sherrod writes that its precise age is unknown and that, judging by similar features nearby, the eruption likely fell sometime between 1.6 million and about 16,000 years ago. The USGS road log and Oregon State University’s Volcano World credit the waves of the old lake with breaching the south rim. Sherrod traces the boundary of the sloughed west wall around to the southeast and concludes that the breach may have come chiefly from crater-wall failure, later modified by wave action.

He dates the 4,440-foot benches to a long stillstand of the lake shortly before 16,000 years ago, the highest water that seems to have touched the rock. The rim lies entirely above 4,500 feet and the summit reaches 4,695, and he finds no sign that the lake ever topped it. The historical marker gives the lake’s greatest height as about 21,000 years ago, when Ice Age bison, camels, horses, and mammoths grazed its shores. Fort Rock is one of almost 40 maars, tuff rings, and tuff cones in the basin, by Volcano World’s count. Hole-in-the-Ground and Big Hole lie off the same highway.

Sandals in the cave to the west

At times the lake grew to 115 feet deep around Fort Rock, and the rock became an island. The state park invites visitors walking the crater to “imagine the early American Indians who canoed to and from” it. Sherrod writes that ancestors of the Klamath, Modoc, and Yahooskin bands of the Northern Paiute lived in the basin more than 11,000 years ago. The historical marker sets out a sequence. About 13,000 years ago the earliest inhabitants were nomadic hunters. By 6,000 years ago people lived in small shoreline houses, ate fish, seeds, roots, and game, and traded for shell beads from as far off as southern California and northern Mexico. Some villages, the marker says, were still occupied as late as 150 years ago by ancestors of today’s Klamath Tribes, Confederated Tribes of the Warm Springs Reservation, and Burns Paiute Tribe.

The Fort Rock sandals came from a cave about half a mile west of the rock, in a small eroded vent the USGS field guide calls Beggars Heel. According to the columnist Finn J.D. John, the rancher Reub Long invited the University of Oregon archaeologist Luther Cressman to explore the cave on his property in 1938. Writing of a later tour, Jim Lough recorded that Cressman dug up 75 sage-bark sandals beneath a layer of Mount Mazama ash. Their age is given differently from page to page: 9,350 to 10,500 years by the state park, 9,000 to 10,000 by the historical marker, 11,000 and elsewhere 14,000 by John. In a historical vignette published in The Nugget, Cressman is quoted as saying, “The record of Fort Rock shows the longest continuous occupation in the Western United States.” Fort Rock Cave was declared a National Historic Landmark in 1961. It can be visited only on a guided tour. On the tour Lough described, the guide was Leslie Olson of Oregon State Parks, and a few cliff swallows were living in the cave. That same day began in town at the Fort Rock Valley Homestead Museum, a collection of preserved homestead-era buildings and equipment that includes a well-drilling rig.

Reub Long’s stadium

By the time Euro-American settlers reached the valley in the nineteenth century, Sherrod writes, it was chiefly Northern Paiute land. The U.S. government used treaties and armed conflict to move the Paiute onto reservations while offering newcomers nearly free land. A wet spell from 1905 to 1920 helped the homesteaders for a time, but drought and killing frosts drove most of them out, and cattlemen took their place. The cattlemen reportedly used the rock’s natural amphitheater as a round-up corral. A 1921 photograph shows a small lookout structure on the west promontory. Another, from the mid-1920s, shows a fire lookout on the south bluff, a spot marked until recently by a benchmark of similar age.

Sherrod says the “Fort” in the name refers only to the shape. The Nugget vignette credits a wrangler named William Sullivan, who on first seeing the walls is made to say, “She looks like a big ol’ rock fort!” Its author warns that some characters in his radio pieces were “created for presentation in a narrative style.”

Reub Long was born in Lakeview in 1898. In 1900 his family moved to a homestead near Christmas Lake, where his mother “kept travel,” feeding and lodging freighters from the four wagon roads that crossed near the place. He and his wife Eleanor built the ranch up to several thousand acres of Fort Rock Valley, part of Fort Rock among them. He wrangled horses for Hollywood on Canyon Passage and The Indian Fighter, and with E.R. Jackman he wrote The Oregon Desert (1964). In that book he admitted, “I don’t lie to people, exactly, but it’s fun to baffle them.” His neighbors called him the Sage of Fort Rock.

The state park records that it acquired the land in 1962 as a gift from Reuben A. and Norma Long, along with lease and deed from Lake County and the U.S. Bureau of Land Management. A McKenzie River Reflections photo caption instead names Reub and Eleanor Long as the couple who deeded the rock to the state. The area was once called Fort Rock State Park and has also been described as a state monument. It covers 349 acres. In 1976 it was designated a National Natural Landmark as a “striking example of a circular volcanic outcrop.”

Long had a larger plan for it. The Nugget vignette quotes him: “Fort Rock would make a perfect football stadium. It’s over a third of a mile across, and you could put tiers of seats on three sides, with the playing field in the middle. That would leave the opening for parking.” Most universities, he said, wait a long time to build a stadium: “Here I’ve got a stadium built and just need a university to use it!”

He died at 76 in the summer of 1974. A photograph in the Oregon State University archives is captioned with his funeral, held at Fort Rock on August 1 of that year.