Mt. Diablo has some really tough climbs - really steep so if you are having a bit of a hard time there, don't sweat it. I can remember many a ride on Mt. Diablo where I was in granny gear, just barely holding my front wheel down on the ground and spinning ever so slowly, slowly up and up and up and up! And, walking some too. So if your heartrate is way up there, that is where it is supposed to be when you climb something like Diablo! It will probably never get better there, cause a lot of those climbs are just what I call
"maxed out" climbs. You are maxed and it is all you can do to stay on the bike (or not)! Hang in there, you stay on longer and longer as you ride that sort of thing, but it takes a while to be able to push yourself that hard.

spoke