The average gas price nationwide is at almost $3 a gallon — the highest it's been in four years — and for those planning summer road trips, here are the states to avoid if you're looking for cheap gasoline.

Between the lines: Axios' energy reporter Amy Harder explains that while there is evidence that President Trump is at least a partial contributor to the rise in gas prices, other factors such as OPEC and Russia, which decided to cut oil production this year, and varying state taxes also have impacted prices.

The top 10 mot expensive states for filing up the tank:

1. California $3.73
2. Hawaii $3.71
3. Washington $3.45
4. Alaska $3.39
5. Oregon $3.34
6. Nevada $3.33
7. Idaho $3.17
8. Utah $3.15
9. Connecticut $3.15
10. Michigan $3.13

The top 10 least expensive states for filling up the tank:

1. Virginia $2.76
2. Kansas $2.74
3. Tennessee $2.73
4. Missouri $2.72
5. Oklahoma $2.71
6. Arkansas $2.68
7. Louisiana $2.67
8. South Carolina $2.66
9. Alabama $2.66
10. Mississippi $2.65