City of Portland. Portland Trails maintains a use-searchable list of trails in the Portland area. You can screen the trails by “wheelchair accessible” or “stroller friendly”. It lists 13 wheelchair accessible trails. The phone for the nonprofit Portland Urban Trails Land Trust is 207-775-2411.
Baxter Woods Nature Preserve is a 30 acre area that offers “… towering pines, river views and quiet, shaded trails” within Portland. The trail is about 0.75 miles and is suitable for wheelchairs and strollers. Very popular with dog walkers.
Fore River Sanctuary is a 85 acre nature preserve within Portland. It came up in my search for wheelchair accessibility, but the trails are not described on the website. Try calling Portland Trails at 207-775-2411 for information on this and other Portland trails.
The Riverton Rail Trail cuts ” a straight line through rock outcroppings and thick forest … the trail is mostly flat and level until a steep gully interrupts the old rail line near Riverside Industrial Parkway.” “Most of the trail is accessible for wheelchairs and strollers.”