You can get some weird results from Mapquest sometimes. I but in here to Moab and get 415 miles through Denver. When I put in a mid point on the way I want to go the results are better.

Home to Gunnison 163 miles, Gunnison to Moab 230, total 393. 22 miles shorter and only one big pass, Monarch. Going the Denver way there are tons of long climbs without names, Eisenhower tunnel and Vail pass. I'd use a lot less fuel going through Gunnison. Depending on traffic and road conditions i'd save a lot of time to.

I guess Mapquest is programed to keep you on interstate at all cost.