Rocky Mountain National Park is a good place to visit if you have mobility problems. Most of the sights can be seen from the car. I have only visited in the fall, the ideal time to see the colors and the elk in rut. I have been there twice now and was impressed both times. The vast majority of the roads are paved and have places to pull off to observe or photograph the sights.
Due to changes in elevation the scenery changes as you drive around. You can go from above tree level down to open meadows where the elk and other animals travel through.
Two of the lakes in the park have accessible trails circling them. They are not the smoothest so it might be a good idea to have someone along if you’re using a wheelchair. Sprague lake also has a trail that goes to backcountry camping.
The Beaver Meadows Visitor Center is designated a National Historic Landmark. Built in 1967, the Visitor Center embodies National Park Service modern architecture. Tom Casey of Taliesin Architects, a design firm started after Frank Lloyd Wright’s death in 1959, designed the building. It exemplifies Wright’s belief in organic architecture, which attempts to integrate a building into its surroundings.