This map details the percentage of state territory owned by the federal government. The top 10 list of states with the highest percentage of federally owned land looks like this:
Nevada 84.5%
Alaska 69.1%
Utah 57.4%
Oregon 53.1%
Idaho 50.2%
Arizona 48.1%
California 45.3%
Wyoming 42.3%
New Mexico 41.8%
Colorado 36.6%