ppine wrote:
Mosquitoes are always around near water in MN. By late August that are not so bad. By mid spetember they are not that much of a problem.
In rural states like SD and WY keep your gas tank more than half full and you will be fine.
^What he said.
Skeeters usually tail off quite a bit by mid Sept unless it's remained extremely warm.
In many years of driving Western States, I feel its never been more than about 100mi to a gas station. However, the easiest peace of mind ever is an extra can of gas if it's of concern to you.
Good luck in your travels!