The hike to Rose Valley falls is a short walk up from Rose Valley Campground. An Adventure Pass is required to park along the road. To meet the logging requirements you will need to do a bit of crawling, get wet (in cold water), and use a flashlight.
As you walk up to the falls the trail passes over Upper Eocene Coldwater Sandstone. It is a marine sandstone with areas of siltstone and shale. Near the base of the cliff the Santa Ynez Fault runs roughly east-west. South of the fault is an Upper Cretaceous mudstone with a little bit of sandstone. This unit was also deposited in a marine environment. Movement along the fault helped create the tall cliff creating the topography of the falls.
Examining the falls will show that the area under the falls actually appears to bulge out away from the rock face of the cliff. This is actually the case. Rainwater is naturally slightly acidic because it picks up carbon dioxide from the atmosphere as it falls forming carbonic acid. This slightly acidic rainwater falling on the Coldwater Sandstone above the falls dissolves minerals, calcium that is common in rocks deposited in a marine environment. Then, as the water flows over the falls, some evaporates depositing the calcium on the face of the falls as calcium carbonate, or limestone. Over time, the falls actually move away from the cliff face.
At the base of the falls, a small limestone cave has formed. You can access this cave by getting low and crawling through the waterfall. Inside the cave, are some typical features of limestone caves.
There are a few small stalactites if you look for them. Stalactites hang down from the ceiling of the cave. As drips of water form on the cave roof, a small amount of water evaporates depositing calcium carbonate. That point becomes the lowest part of the ceiling, so more water drips form in the same spot further lengthening the stalactite. Stalagmites form on the cave floor under the stalactite. A small portion of the drip evaporates as it hits the floor again depositing some calcium carbonate growing a mound up.
The walls of the cave are rippled and there are a few shelves. Be careful not to damage anything so that others can enjoy the cave.
Send me a note with:
- The text "GC2CY5P The Cave of Rose Valley Falls" on the first line.
- The number of people in your group (put in the log as well).
- How many rooms (they are small) are there in the cave.
- Based on where the water is dripping, what part(s) of the cave is growing.
- Find a stalactite and measure how long it is?
- Is there a matching stalagmite?
The following sources were used to generate this cache:
- Kellogg, K.S., Minor, S.A., and Cossette, P.M., 2008, Geologic Map of the Eastern Three-Quarters of the Cuyama 30’ x 60’ Quadrangle, California: U.S. Geological Survey Scientific Investigations Map 3002, scale 1:100,000, 2 plates, 1 pamphlet, 23 p.