@Earthmom, I'm not a fan of crowds either! Here are a few of my favorites.

  • As far as non crowded parks go, I really like Lassen Volcanic National Park (peaks, all kinds of volcanic activity, they have a place called "the fantastic lava beds" that lives up to its name.
  • Also, Great basin national park is an amazing destination (lakes, glacier, awesome caves).
  • Lava beds National Monument is surprisingly amazing. You get to walk through tunnels and caves created by lava flow. The amount of exploring available is awesome.