Yeah, that 3,735' in 12.4 miles works out to a tad stiffer than 17-1/2' for every linear foot ridden, 301' per mile.

There's a stretch near where I live that's ~ .66 mile inn length, climbs 260' bottom to top. I use it as a 'challenge' hill, tells me where I'm at in very specific ways.

If that were 12.4 miles long (gasp!) the climb'd be not quite shy of a mile, ~ 1,000' more than Mt Diablo demands.

Tough ride!