I am a quarter Native American and three quarters white. I am unsure what I should list on my applications.
Also, how do they determine minority status. Is it from your profile on the LSDAS or from the application.
I'm 1/4 NA too (Muskogee). I agree you should think about which you identify with more. For example, I've checked NA off since I was 6 and took my first standardized test... because it has always been a part of who I am. And make sure you have something to write about in your DS to show your connection with your heritage. (ie. I wrote about my work with Native American Studies at UF and my relationship with my paternal grandmother)
Anyways, what tribe are you? (Just curious)
EDIT: And yes, a tribal number helps too... though in my case this was impossible... didn't seem to hurt me though.