Idaho?

I remember being in Idaho back in the sixties when I was kid. I'm not sure what we doing there. Maybe we were on some family vacation in our red squareback VW or perhaps when we were moving to California from New Hampshire. All I remember is being in Sun Valley, Idaho, which is a big ski resort, in the middle of the summer and it was hot. I remember being in a hotel or restaurant, someplace kind of nice, but they had what looked like aluminum foil in these neat square panels on the walls and people had pressed or scratched their names and initials all over the walls. I thought it was the coolest thing.
That's all I remember of Idaho.