National Parks

I'm trying to find a park I visited 10-15 years ago, but Google searches and ChatGPT can't find it.

What I am confident about:

1. The visitor center had the bathrooms downstairs, and a wall near the bathrooms was painted with information about trying to become a national park.
2. It started out as a place where troublemakers were sent, but was used as a base to scout and detect invasions from the North.
3. It was there for a long time, then the military branches were established and this became a military base.
4. There are officer buildings left from when it was a base. I think they were duplexes with a brick wall separating the sides, and some buildings had one side of the duplex removed. A lot of the buildings were white.
5. The officer buildings were in a grid layout.
6. Several long roads with scenic views.
7. At that time, when entering the visitor center to the right it had a display with various taxidermy animals plus buttons to push to hear what they sounded like. To the left was the gift shop.

What I sort of remember, but not positive about:

1. I think it became an Army base, and the people became part of the special forces.
2. I think it had Fort in the name.
3. I think it was close to a mid size city, like 15-30 min drive.
4. It was for defending from the North, but it was not on the US/Canadian border. It was much farther south like Oregon-Wyoming line. It stands out as I thought it was pretty far away from the current border.

If anyone has information I would greatly appreciate it.