The top 10 list of states with the highest percentage of federally owned land looks like this:
1. Nevada 84.5%
2. Alaska 69.1%
3. Utah 57.4%
4. Oregon 53.1%
5. Idaho 50.2%
6. Arizona 48.1%
7. California 45.3%
8. Wyoming 42.3%
9. New Mexico 41.8%
10. Colorado 36.6%
Notable is that all these states are in the West (except Alaska, which strictly speaking is also a western state, albeit northwestern). Also notable is the contrast between the highest and the lowest percentages of federal land ownership. The US government owns a whopping 84.5% of Nevada, but only a puny 0.4% of Rhode Island and Connecticut. The lowest-percentage states are mainly in the East, but some are also in the Midwest and in the South:
1. Connecticut 0.4%
2. Rhode Island 0.4%
3. Iowa 0.8%
4. New York 0.8%
5. Maine 1.1%
6. Kansas 1.2%
7. Nebraska 1.4%
8. Alabama 1.6%
9. Ohio 1.7%
10. Illinois 1.8%