Thanks, Earl.
The reason I asked was that several of us, four to be exact, were on a special snow clearing trip out of antonito in the spring of 1999 and found a similar situation around about, I think, mp310 or so. I was on top of a cut hoping to get some video of the section blasting the rock but at the last minute, Bart decided it might be too dangerous so all we got to do was listen and then view the aftermath. Come to think of it, I'm sure the rock was considerably smaller than the one in "Trains". Les Clark