Thanks for the info and the re-write. I ran across an article that makes a few suggestions that would be great but most of them were international (Vancouver was mentioned). The domestic locations I recall are few locations on the front range of the Rockies. You can take Amtrak from Denver to Winter Park/Fraser and Glenwood Springs. Or you can take RTD public transportation to Nederland which is in Rocky Mountain National Park.
Maybe some other readers know of some more obscure options out there. Some of the best parks I have been to were very small and unheard of. I just hate have to spend hours behind the wheel to get there. I'm getting to feel like public transportation is kind of a vacation from driving.