Well fella's I am booked on combination hunt next year with 3 tags in my pocket. Mountain Goat, Elk and Mule Deer. I bought a 300 Ultra Mag to take but now I am wondering if my old faithful 30-06 wouldn't handle the job if any one of the three presented itself. What do you think?

Rebel,

the 30-06 would certainly do the job, but since you have the ultra I would use it.

Ya... use the .300 ultra if ya got it.

I usually hunt with a 30-06 and have taken Rosevelt elk, mule deer, blacktail deer, and mountain goat, all with a 30-06 mostly with 180 grain bullets. I think the elk are the toughest to put down but still not a problem.

I would take both and use one as a back up rifle. The ultra may be better suited for the very long shots you might encounter with the mountain goats but I would still choose which ever one that you shoot better.

The 30-06 is certainly more than enough gun for any of the three you listed.

I would go with the 300 RUM. Good luck.

Take the one you shoot the best, its not what you hit them with, its where you hit them at.

300 WBY

personally i would go with 30-06 that's just me. it's a great cartridge for the game you're wanting to hunt or larger.

Looks like your decision is already made unless you are thinking about taking the 300RUM back.
Follow thru on your original plan and take the 30-06 along as the back up rifle.