My wife and I did this.
I got out of the military, and we both had no job, no bills, no car, but plenty of cash. So we went on an around the world vacation for two years, part of that included buying a truck and driving not once, but twice across the US visiting every national park and point of interest there was.
We wanted to go up to Alaska, but we decided we were finished with the around the world vacation and had to return to "normal" life. The Alaska trip will be soon enough when I get a 4runner.