Not much in the way of ADA guidelines, but you can access the parking/picnic area at Andrea's Canyon. Its undeveloped though, so pushing a wheelchair might be rough. Check with guard gate at entrance.
I think that a person on the wheelchair can enjoy the view of the canyon from the top, so I would not discourage you from your visit! But indeed the most of the canyon is for hoking.
Not really only to concession. The first part of the walk is down a steep winding skinny path, maybe 100 ft down then it would be extremely challenging after that. Nearly kicked my butt
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