Location: Christmas Valley is located in Central Oregon, about 70 miles southeast of Bend.
What You’ll See and Do There: Camp, walk and hike, drive or bike the Oregon Outback National Scenic Byway, bird watch, fish nearby lakes and streams, mountain bike, explore historic and pre-historic cultural sites.
Geology: Desert wildflowers and tufts of bunch grass nestle among the sage and rabbit brush carpeting the floor of Christmas Valley. But until about 10,000 years ago this was the bottom of a massive lake 40 miles long and 25 miles wide. Lush vegetation probably grew along its shores, providing habitat for Pleistocene mammals like camels, mammoths, and huge ground sloths. Some of these animals may have witnessed earthquakes and volcanic activity, which were common in the area. One of the more spectacular eruptions would have been the formation of Fort Rock, sometime between 100,000 and 50,000 years ago. Lava worked its way up from deep in the earth and burst into the lake. When the hot lava encountered the cold lake water, it exploded in a violent eruption of steam and shattered rock. A wet slurry of ash and mud was tossed high into the air, then splattered back down in sticky globs. As the eruption continued, the globs piled up in a ring around the volcanic vent. The ring grew higher and higher until it eventually towered above the surface of the lake. The hot, sticky globs welded together as they cooled and formed a solid ring of rock called a tuff ring. Over time waves carved through the southeast side of the ring, leaving behind the crescent shaped amphitheater we see today. Wave cut terraces can be seen at the base of the cliffs on the south and east sides of Fort Rock, where the sheer cliffs walls rise up from the old lakebed.
There are more than 30 volcanoes in the Fort Rock Basin that erupted into water. Most of them formed tuff rings similar to Fort Rock, but in some cases the rings filled with a molten lake of lava after the explosive phase of the eruption was over. The basalt cliffs of Table Rock are the remains of a lava lake that filled the middle of a tall tuff ring. Other eruptions were so violent that instead of building up tuff rings, they tore huge holes into the earth. Hole-in-the-Ground is a spectacular example of a maar, or explosion crater, that formed when rising lava encountered water. The eruption occurred on higher ground, not in the lake itself, but there was plenty of ground water that generated a violent steam explosion. Huge pieces of rock and earth were ripped up and thrown from the crater. The eruption of Hole-in-the-Ground tore open a crater almost 500 feet deep and more than a mile across.
Not all of the volcanoes in the Fort Rock Basin erupted into water. The desolate black lava flows of Devil’s Garden, Lava Mountain, and Four Craters could have formed tuff rings or maars similar to Fort Rock and Hole-in-the-Ground, but the lake was either gone or had shrunk to a much smaller size when these eruptions occurred, and the rising lava did not encounter water. Although there were no violent eruptions of steam and fractured rock, there were fiery eruptions that built cinder cones. Earthquakes accompanied the eruption of the Four Craters lava field, ripping open long cracks in the ground. Lava poured into the cracks, filling them up in some places, but at Crack-in-the-Ground the gash is still open and can be explored. Entering the crack is like entering another world – the path descends into a narrow slot between high rock walls, the desert dryness is replaced by cool moist air, and the sky becomes a narrow band of bright blue high above the chasm.
More Geology
Fort Rock Field Guide
U.S. Geological Survey Cascade Volcano Observatory
Vital Stats:
Christmas Valley is located on the northern edge of the Great Basin and is surrounded by sagebrush wildlands and unique geological features. This sparsely populated region ranges in elevation from about 4400 feet to about 5000 feet. Fort Rock State Park is open daily year round. Hole-in-the-Ground and Crack-in-the-Ground are always open, but winter snows can temporarily make access roads impassable.
How to Get There
From US Hwy 97 just south of La Pine, go southeast on OR Hwy 31/Fremont Hwy and follow for 25.2 miles, turn left at Forest Road 3125 and follow for 0.8 miles, stay left on Forest Road 3125 and follow for another 0.8 miles, turn left at Rd 017 and follow for 0.7 miles, turn right at Rd 400 and follow for 250 feet, turn right at Rd 220 and end at Hole-in-the-Ground overlook.
From the junction of Forest Road 3125 and OR Hwy 31/Fremont Hwy, continue southeast on OR Hwy 31/Fremont Hwy for 4 miles, turn left at County Rd 5-10 and follow for 6.4 miles, turn left at Cabin Lake Rd and follow for 1 mile, turn left at County Rd 5-11A and follow for 0.6 miles, turn right at Fort Rock State Natural Area and follow 0.2 miles to parking lot.
From the junction of Cabin Lake Rd and County Rd 5-10, continue on County Rd 5-10 for 15.9 miles, turn left at County Rd 5-14/Christmas Valley Wagontire Rd and follow to the small town of Christmas Valley. Continue past the Chevron station for a little less that half a mile to a brown sign on the right that reads “Crack-in-the-Ground Rd,” turn left and follow the gravel road for about 7 miles to the parking area. Follow the trail 0.2 miles to the crack.
Google Map
Fees and Parking
There are no parking or entrance fees Fort Rock State Park, Hole-in-the-Ground, or Crack-in-the-Ground.
Nearby Parks and Attractions
Christmas Valley Sand Dunes
Fort Rock Cave
Fort Rock Valley Historical Homestead Museum
Lost Forest
Nearby Food & Lodging
Food
Cowboy Dinner Tree
The Lodge at Summer Lake
Lakeside Terrace Restaurant: 87275 Spruce Ln, Christmas Valley, 541-576-2309
Camping
Green Mountain Campground (no water)
Lodging
Cowboy Dinner Tree
Lake in the Dunes
Lakeside Terrace Vacation Rentals: 541-419-2826
The Lodge at Summer Lake
The Marlette
Summer Lake Hot Springs
Regional Visitor Center
Southern Oregon Visitors Association
Hotlinks to More Information
Christmas Valley Chamber of Commerce
Christmas Valley Information
Fort Rock Sandals
Fort Rock State Natural Area
