Pretty nasty pic. Some Crotalus venom is both hemotoxic and neurotoxic. Cortalus scutellatus (Majove Rattlesnake) has both toxins, as does Crotalus durissis (Neotropical Rattlesnake). Pretty nast what the combination can do to you.
C. oreganus has relatively weak venom. I've never actually heard of a human fatality resulting from a bite from one. My wife's grandfather is a retired surgeon, and he is one of the few doctors around here to have used the anti-venin for the species. He also can't recall reading or hearing of a fatality as a result of C. oreganus. That's not to say I'm taking any chances, since I am allergic to anti-venin.