"...We liked to drive in from Sunset. Is the old Right of Way still accessible?..."
Rick - By the time I was a teenager (decades ago, but not as many as for you), Glacier lake was a gated community, so I have never been inside.
The thick blue line is the Peak-to-Peak highway, the dsahed blue is the old highway, red is the grade and yellow the approximate location of the fence. The grade coming in from the right (from Sunset and Sugarloaf) is diverted to the old highway, then ends at the modern highway. The grade coming in from the left is hard to find, but much is still there. I believe the fence surrounds the lake and development, so it's blocked even if you come up Pennsylvania Gulch (top right corner of the image) from Sunset. The trees and curves in the roads and railroad grade prevent getting a glimpse of the lake or the site of wye and pavilion (long gone) from public areas.