Park Number: 2/61
First Visited: Undocumented
There's a unique sense of pride, for me, that comes with this park as it's technically the only fully-fledged Montanan national park in the system (MT only claiming 3% of Yellowstone). This park also has, quite possibly, the most dramatic mountains in the United States. Thus far I've only seen comparable glacier-cut valleys in the Fiordlands of New Zealand.
When visiting Glacier, traversing the Going-to-the-Sun Highway is a must, hiking the ample trails is recommended (I'm keen to the eastern side, especially Lake Mary), and heading into Waterton Lakes National Park on the Canadian side is a nice added bonus if you've got the time (and a passport). Lastly, bring your bear spray—grizzlies are ample in this region (with an estimated 1,200 in the park).