The Chama Yard detail on Ernie's large map of the C&TS published in 1970 shows the westbound track ending a car length or two beyond the wye, but doesn't show the by-then-abandoned track(s) into the lumber yard.  There's a good map of the Alamosa yard in the Final Years book he co-authored with Joe Hereford (© 2001), but – somewhat surprisingly – no detail map of the Chama yard during the Rio Grande days.

I don't remember how far the second track extended on Sept. 6, 1970, when a gang of us "borrowed" a long length of rail from the abandoned line to repair the Highway 17 crossing on the north side of town.  (Lucky for us, the D&RGW had already pulled the spikes, but not yet picked up the rail.  Our heaviest "work" consisted of un-bolting a couple of joints.)