gpserror
Seems Colfax used to be a fairly important street, so important that it could have been made into a highway.  However they apparently decided not to. 

As there are traffic light (i.e. at grade) intersections fairly close I'd say it should be left as a primary and not upgraded as a trunk.  They probably built an almost complete cloverleaf here because US287 is equally an important road and a lot of people would go through this intersection in all directions.  And thus whatever Federal is, Colfax should be as well.

Other comments would be appreciated but this is my two cents.