All along the roads in RMNP you will see (even in Summer) poles of various heights.  The poles are there to tell the snowplow operators where the edge of the road (i.e.: the 'plowable' area) is.  The poles are tall enough that in the worst of conditions they will still show above the tops of the drifts.

Draw your own conclusions.

This picture was taken at RMNP's Alpine Visitor Center, elev. 11,796 ft.  We haven't seen a tree for miles.