Maybe the QS ranking will be of help?
https://www.topuniversities.com/university-rankings/university-subject-rankings/2017/geography
Based on QS, the Top 20 in the US are the following:
UC Berkeley
UCLA
University of Washington
University of Wisconsin-Madison
University of Chicago
University of Minnesota
Ohio State
UNC, Chapel Hill
Arizona State
Penn State
CUNY
Clark
Indiana University Bloomington
Michigan State
UC Davis
UC Santa Barbara
University of Colorado Boulder
University of Illinois at Urbana-Champaign
Boston University
Dartmouth