Doug,
I guess it depends on your definition of "much". The depot is still here in its original location - it's even painted in proper Rio Grande colors. The water tank was dismantled about 10-12 years ago and placed in storage for future reassembly somewhere. I'm not holding my breath.
I've hiked much of the Floresta Branch and all of the Smith Hill/Anthracite Branch. Not much left of either, other than some trestle ruins.
The south side of the South Park's Ohio Pass line is pretty interesting, at least to me. Construction was ongoing in several locations along the grade when they gave it up. Partially completed fills and cuts and rock culverts give insight into the construction techniques of the era. There's even some grading for the wye at the top of the pass. And of course the half-finished rock wall is pretty spectacular.
Regards,
Matt