Well, a 400 ft climb with parts at 7% are part of my commute out of the El Cajon Valley each workday here in the San Diego area...generally, you can find a well engineered highway that crosses any western mountain range, but also find plenty of other crazy steep options. For example, you can climb up the Lassen Park Road from 5000'-8500' and never break 6-7% grade, or cross the Sierra at Yuba, Donner, or Tioga Pass at no more than 6%, maybe 7% in spots. However, the Sierra's Ebbetts and Sonora Passes feature some stretches of over 24%, and other sections have sustained climbs of over 12%. Overall, the parts considered "tough" climb between 3 to 4 thousand feet. Heck, here in San Diego County, though maybe topping out at 8%, the Montezuma Grade from Borrego Springs climbs 3600 feet in 11 miles, and the South Grade up Palomar Mountain climbs from 800' at Rincon to over 5260' at the summit...(the hiker-biker site at the State Park on the top of the mountain seems to have had very little use for some reason, the table was under a foot of leaves and I had to get a rattlesnake to leave the site by launching it with a stick (they hate to fly!)