Ole's Cave is named after Ole Peterson, who discovered it while exploring his property in 1894. It is about 6500 feet long, making it one of Mt. St. Helens' longest lava tubes. It is managed by the US Forest Service. Much of the interior is as large as a train tunnel, but there are some short sections you will have to crawl through. There are also multiple deposits of breakdown that you will have to climb over. None of this breakdown is recent - it occurred when the cave was cooling after the lava stopped flowing through.
Interesting features to look for inside are:
• Rings on the cave floor where material from the ceiling fell into cooling lava below, which hardened before the impact's splash ring could flatten out.
• Thickened ridges running lengthwise marking the height of the lava during different flow episodes.
• George Washington's head, a lava formation that looks just like his profile on a US quarter (except he's facing the wrong way)
• Fern gardens growing on the walls of some of the openings along the length of the cave. The flora in these openings is delicate and should not be stepped on, so do not attempt to exit the cave at any of these locations.
This cave serves as a hibernaculum for Townsend's Big-eared Bats and is closed from November 15 - April 15 to protect them. The Forest Service encourages visits during the summer months when few, if any, bats are present.
Parking can be found at N 46° 04.599 W 122° 12.643 - This is an active logging road so do not block the gate or your vehicle may not be there when you return.
Leave the logging road at N 46° 04.102 W 122° 12.679 and follow the faint trail through the moss to the cave entrance. On the way, be on the lookout for fascinating lava formations that include gigantic burst gas bubbles, collapsed small lava tubes, and casts of trees that were ultimately destroyed by the lava flow - but not before the lava hardened around them.