Colonize Interior

[Castellon]

I have a colony on the coast of NA. I send a conquistitor into a non coastal provence beside my colonyLv1 provence. When I try to colonize this provence, the send colonist button is greyed out. It will only let me send a trade post.
My question is: Are all the provences in the Americas colonizable or are there some that you can only set up a trade post. The manual hints that there are some provences where this is the case but hints that these are in Africa. Or do I need to get the Adjacent colony to city status before I can colonize?
Does anyone have a list of the provences that can only be TPed not colonized?

 

[Castellon]

Thanks for the quick responce, I figured it was something like that.

 

[Castellon]

In this time frame, I don't know that you could have sailed a warship into the great lakes. The St.Lawrence seaway was a big undertaking.