OC is legal in most places but unless you are the wood or rural areas you might get some grief.  With the amount of tourists in RMNP I would not OC.

You can carry in the National Parks here but you can not carry inside the facilities.  That is,  the guest shops, restrooms and such.  But this is true at all national parks not just the ones here.

I've actually OC'd in RMNP with absolutely no problems.  In fact I called them in 2013 when the law changed and they were very straight up with fact that the park has to allow both concealed and open carry

Not exactly correct.  

You cannot carry in any facilities that contain administration offices.  Restrooms are not off limits (provided they are not in a building marked with the emblem), nor are certain gift shops, particularly, the one at the top of trail ridge.  The key thing is the building has to have the white circle with the black firearm in it and a red line through it.  If it doesn't have that you can carry in there.

Thank you for the clarification.  
I did not know that.  

I may or may not have carried past just success a sign in the past though.

Motorcycle trip though a np and stopped for a restroom break.  My options as l saw them were to pee my pants,  pee in the parking lot,  remove gun in the parking lot - in front of Lord only knows how many people - and then in full site stash it in unlockable saddlebags,  or keep it on me and hope no one notices.

Truth is l don't remember if there was a sign.  There is a gift shop and small theater so there probably was.