As I understand it, ice caves generally form when an avalanche of snow falls over the side of a mountain, or a glacier, and then compacts into a big pile. Then water runs off the side of the mountain / glacier (usually as a waterfall) and starts to erode the underside of the snow-pile, until it forms these giant caves. Daniel estimated the cave we visited to be about 30 feet tall.
These ice caves are situated at the end of a very mild 1 mi trail in from a trailhead that is adjacent to a parking lot. However, both times I've been to this trail, the parking lot adjacent to the trailhead has been blocked. We parked at the gate that was closing off this road. I spoke with a ranger to get the scoop on the trail, because I had heard rumors that this summer's floods and storms in the mountains had ruined this trail. She confirmed that the bridge had washed out, but that there was a large log that all ages of people were using to cross the river. Her official position, of course, was not to go, but she said personally she thought it would be okay, unless it were raining (since the wood can get pretty slick).
As you can see from the pictures, we made it across the log and to the ice caves. In this picture, Daniel and I are prety far in front of the ice caves, and the perspective is making the ice cave entrance appear a lot smaller than it really is.
Here is a picture I took of the beautiful forest that surrounds the rock-field where the ice caves are located. It is just so lush and mossy... I love it!
Here is a picture of the bridge that was washed out. To the left, you can see a small wooden box-ish thing with a yellow sign on it. That is the other end of the bridge. The trees and wood to the right of the picture are mostly fallen logs, but to the right of those (out of the picture-frame), there were some large (LARGE) pieces of the bridge that had ended up as mere lumber in a pile on one side of the river.
We were also lucky enough to see some of the first snowfall of the year. It looked like someone had dusted the tops of the mountains with powdered sugar. Kris lamented that her camera would not do justice to the contrast of the snow on the pines, and make them blend into the grey sky. I feel the same way, however, I think I was able to catch some of the contrasts of the snow-topped mountains, as well as the beautiful forest through which we walked.