Upper Snake has been closed for several years, but I haven't been over to it for a while. It basically runs straight down a bank over a temporal streamcourse and is prone to alot of erosion and the original line is not sustainable.
Early on, it seemed the City of Burnaby was going to re-route the trail and re-open it, as there is a viable line down that way that is more circuitous and off the bank, but generally, it's just become closed.
That said, I have heard that with the closure of Gear Jammer, more and more folks have been riding it again. Perhaps I'll ride home along Mel's tonight and see if there is obvious signs of action.