Central Oregon down under
My two nephews from Missoula, Mont., are visiting for a week and after a few days of hot hiking, we decided to head underground.
Few places on earth are as dark and quiet as the inside of a cave. There's a kind of impenetrable darkness and total silence. When we flicked off the lights, we were engulfed by the darkness. Not the kind you might expect on a moonless night; there were no stars, no distant lights. The darkness was absolute, total. We could not even detect our hands a few inches from our faces.
There are literally hundreds of lava tubes in Central Oregon. The Deschutes National Forest has more caves on it than any national forest in the country - about 400, although most people only know about the more popular ones.
The first of the day's caves was Lava River Cave, the longest lava tube in Oregon at almost a mile long. In places, the cave is 58 feet high and 50 feet wide.
Thousands of years ago, lava flowed from the flanks of Newberry Volcano creating a channel. The sides of the channel eventually crusted over, forming a roof, while the fluid lava continued to flow. A hollow tube was left after all the lava drained out.
Lava River Cave gently slopes downhill toward the Deschutes River. At 1,500 feet in, Highway 97 is about 50 feet above the roof of the cave. Much of the cave's floor is covered with sand. It was once thought that an ancient river flowed through the cave, hence its name. The sand did get into the cave by water but not from a river.
Sand on the ground above the cave worked its way into cracks and was carried down into the cave grain by grain from the movement of water. Some sand could have directly got into the cave through larger cracks and from the mouth.
This process would have taken thousands of years. Lava River Cave is estimated to be about 100,000 year old. At the end of the cave is a sand plug. No one knows how much farther the cave goes past here. Two people dug out the last section back in the 1930s but finally gave up. From the entrance to the sand plug the cave drops gradually about 200 feet in elevation
Halfway into the cave is a section known as "two tube tunnel." There, a smaller tube within the larger tube runs about 100 feet. Volcanic stalactites known as "lavacicles" hang from the cave's ceilings and walls.
Collapses in lava tubes can occur from cooling and shrinkage after the lava flows out, from freezing water that dislodges rock or from earthquakes. Without these collapses, the caves would not be discovered. From the entrance of Lava River Cave, the main tube heads northwest for about a mile. The section to the southeast continues for another 1,560 feet, but is closed to the public due to loose rock.
Bats use Lava River Cave and several other caves in the area for hibernating during the winter. Most are out by this time of year. Do not disturb any bats that you happen to come across.
After being in the cave for an hour or two, coming back to the warm surface feels like walking from winter right into summer.
Our next stop was Boyd Cave, a lava tube 1,880 feet long. As we headed down a set of metal stairs, we were immediately greeted with cool air hitting our faces. When warm air hits cooler air, the end result is moisture. This accounts for all the interesting and unique vegetation at the mouth of the cave, which creates its own mini-ecosystem.
No matter the temperature outside, the lava tube remains a steady 45 degrees year-round, so be sure to dress warmly and wear a sturdy pair of hiking boots. A headlamp and a small flashlight are suggested, and watch for low-hanging rocks if you don't want to come back out with a lump on your head. There are a few collapsed sections that make for more difficult walking.
These Central Oregon lava tubes have quite a history. They were first used by Native Americans and later by white settlers as refrigerators. Remnants of whiskey stills have been found in some. The government even looked at a few of the caves for use as bomb shelters.
There were a few places where all of us had to get on our bellies and crawl through smaller passageways. Anyone suffering from claustrophobia may want to remain in the larger portions of the cave. Through these small openings, we could feel the air blowing by us. As the barometric pressure changes outside, the air will move in and out of the lava tubes. It's almost like the caves are alive and breathing.
There's a spider-like creature that calls the cave home. It's called a harvestman and is very similar to a Daddy Long-legs. The harvestman is not a true spider; it has 10 legs with the front two used to capture its prey. We did spot one toward the end of the cave.
We also saw some rootlets hanging down from the roof of the lava tube, which were most likely from large ponderosa pines. The cave floor at the entrance is about 30 feet below the surface, while the end of the cave is about 60 feet below the surface.
My two nephews enjoyed the day of spelunking. "I like the absolute silence of being in a cave," said Quinn, 17.
"I like the adventure of not knowing what's around the next bend or through the next crawlspace," said Nolan, 15.
To reach Lava River Cave, go 12 miles south of Bend on Highway 97. The turnoff to the cave is about two miles past Lava Lands Visitor Center.
To get to Boyd Cave take Knott Road at the south end of Bend and go east 1.3 miles, then take a right on China Hat Road. This road turns into Forest Road 18. Go 8.1 miles and take a left on Forest Road 1819-242.
Boyd Cave is only a few hundred yards down the road. The road passes through the Skeleton Fire, which burned 17,000 acres in August of 1996.