I'm currently svck in the storyline, I really want to help the Great Khans, but one of the peeps is at the very end of Quarry Junction. Try as I might, I can't sneak or fight my way though. Rex and Boone die instantly from a single Deathclaw attack and I have to hop around downing drinks and Stimpacks to stay alive, before eventually dying.
I've tried Flamer, Rifle and even Dynamite against them! Nothing seems to work! Its quite easy with Boone's and Rex's help against 1 but no matter which way you go in the quarry, you end up getting piled.
Whats the best way to kill or sneak around the Deathclaws?
Best way (still tricky, but not
quite as bad) is to not take the "Hi Diddle Diddle, Straight Up The Middle" path through the quarry.

Locate Vault 19. Come out of its parking lot, take a right up the road, take the first "pathway" to the left. (Easily spotted as there's usually a Deathclaw of some stripe pacing around it just off the paved roadway)
Cautiously advance up that path, you still have to cross a field of Deathclaws but in my experience they're not as..."tightly packed in" as the ones in the quarry, and there's a path through the back wall of the quarry to the Khan encampment you're trying to reach. Said encampment also makes a nice perch to clear the quarry itself from later.