The following are detailed sections of Equinox: Equinox Mile 1 (10%).
The access road to the top of Equinox, tucked next to a couple buildings, looks a bit like the entrance to some crazy amusement park ride. It's as steep as Mount Washington and longer than any of the similar hills (Okemo, Ascutney) in the northeast, except Washington. The website for the hill climb (also the only time you're allowed to go up it) lists a maximum gradient of 28%. This measurement was probably taken on the inside line through one of the switchbacks, because I didn't see anything that seemed that steep when I climbed it.
Equinox is located in Vermont. It is 8440 meters long with an average gradient of 11.6% and a maximum gradient of 18.9%. Find similar hills.