Maybe others can fill in some of the specifics, but the general story goes like this:
In October of 1922, a helper engine (most likely a C-16 I'd guess) was heading eastbound when it met up with the westbound passenger train headed by 169. The engineer and fireman on the 169 were killed and at least one of the engines went over the side ending up about 50 feet down the hill. Apparrently the engineer on the helper mis-read his orders and thought he had more time to get to Sublette than he actually did.
The remains of one engine's pilot and a coupler is still at the scene, along with some fire bricks coal and other miscelaneous bits.
The pilot used to be visible from the train, however it's been a few years since I've seen it, I think the bushes have grown up to the point that it's hidden. Next time someone's out there with a chainsaw, maybe this can be rectified. However I was able to snap this photo of it from the train back in Sept. 1996.
Don