Fort Harrison State Park
The main sledding hill at Fort Harrison is long, wide, and fairly steep.
It can accommodate a lot of people sledding at the same time—which is good because on good sledding days there can be a lot of people there.
One nice plus: there is a path along the "edges" of the hill for people to climb to the top, without fearing being mowed over.
Sledding at Fort Harrison State Park is allowed on a massive hill in the center of the park — but you must pay the $5 entry fee (it’s worth it!).