I've always reckoned that 50ft/mile is an average ride, anything less than 25ft/mile is a flat ride, and 100ft/mile is a pretty hilly ride (though I've always worked in m/100km).
Back in the old days before AAA points had been invented, any event over 22m/km (115ft/mile) was a "super grimpeur", and qualified you for a gold badge. Mind you, that was worked out by contour counting on paper maps, and that doesn't read as high as a GPS does. You probably also had to do the full 200km too.