go back at level 17+ and bring the best weapons you can, preferably explosive or long range... why the hell didn't you listen to all the people telling you NORTH IS BAD!
If you have them, use Bottlecap mines to cripple the Deathclaws, they slow to a crawl when their legs are damaged.
Be aware, 2 Boss level deathclaws are in the quarry. A matriarch (huge deathclaw) and a patriarch (average sized, but darker skin tone)... the latter can kill a level 20 player with medium endurance in power armour in 1 swipe.
EDIT: Don't go back there until you're level 18 (better leave it until level 20) have 90+ in explosive, guns or energy weapons and have a few associated perks that buff those skill sets.
High DAM weapons are you're friend, low DAM will do you no good. High Critical chance is also good (finesse and better crits, and any weapon that naturally gives high crit hit chance).
EDIT EDIT: If your playing on Hardcore, don't bring any melee companions (like rex or lilly) as they will get DESTROYED (and you lose them permanently on Hardcore).