elite check-in/boarding
 

I have NW Gold, if I get CO miles instead of NW miles on a CO flight can I still use elite check-in and get elite boarding if I show my NW card?

yes you can.
you can even do that with other Skyteam airlines.

Should be able to even while crediting miles to NW.

It's been a while since I was on NW, but got early boarding and miles went to my CO account. This should be same for NW fliers on CO.

EmailKid

Thanks, also since my BP won't show my status since the miles are being credited to a non-elite account can the agent manually change my boarding zone or will I have to show my card during boarding?

I don't believe that they'll do this step for you. At least, I once witnessed an NW Platinum (maybe it was DL, but I am pretty sure he was NW) who was transferring to CO. He visited the PC at LAX and tried to do exactly what you stated. They suggested he just board first, but show his NW Plat card.

CO doesn't do "Zones" on the boarding passes. Just board when they call elites, and have your card out, though they are most likely not going to ask.

Are you planning on switching from NW to CO? Just curious why you'd be crediting the non-elite account.

I have some CO miles that I want to use, but I need a little more.