Tucked into the Lenore Canyon are the Lake Lenore Caves. Along with much of the eastern half of the state, Lenore Canyon was formed during the Missoula floods at the end of the last Ice Age, over 13,000 years ago. The glacial flood waters crashed down the canyon, carving through the basalt that makes up the sheer rock walls, creating coulees, ridges, cliffs, plateaus, rock slides, caves and a series of lakes.
The caves themselves are shallow, created during the Great Missoula flood as water pulled chunks of basalt from the walls of the coulee. Post-flood weathering created talus slopes that furnished easy access and temporary overnight camps and storage for at least 5,000 years for hunters and gatherers from villages located elsewhere in the Grand Coulee and along the Columbia River and its tributaries. It is still used today for certain Native American religious ceremonies. It is easy to see why the caves were chosen as a cozy place to stay, as the depth provided plenty of shelter from the elements, while not going so deep that light couldn’t reach the back corners. It is often quite warm and breezy outside, but in the caves it is cool and calm.
A well-marked 1.2-mile out-and-back trail leads from the parking area to some of the caves. It is generally considered an easy route that takes an average of 31 min to complete. This is a popular trail for hiking and walking, but you can still enjoy some solitude during quieter times of day. The best times to visit this trail are March through November. Dogs are welcome, but must be on a leash.
The coulee walls in this area are made up of Grande Ronde Basalt flows overlain by the Frenchman Springs and Roza members of the Wanapum Basalt. The lower (colonnade) and upper (entablature) cooling units of individual flows are visible in the coulee walls. Flow unit contacts are sometimes complex to interpret. Some flows pinch out against older flows, some are perhaps due to flows covering an irregular topographic surface on the underlying flow, some may be filling of shallow valleys, and some multiple layers may be pulses of lava from the fluid interior pushing out over the partially formed entablature of a previous lava pulse.