No question, the Highline is the worst of the very best trails in Glacier. On the one hand it’s extraordinary scenic, cutting a bold traverse right along treeline through one of the steeper walls in the park. You almost always have complex, 5th class crags above you, and steep green slopes (and the road) below you. On the other hand the popular part of the Highline is, when down out to Granite Park chalet and down to The Loop, as we did, almost all downhill, and with easy access comes lots of people. Lots of people; M counted over 40 in view early on, and I bet close to a thousand hike at least the first few miles on any sunny summer day. Passing is a nuisance, and the miles beat you with unexpected rapidity, as most of the dirt is hard as asphalt. The Highline is the alpine sacrificial lamb of Glacier National Park, as it may be the furthest many folks every get from a road in the alpine, and hopefully the noise and visual pollution are justified by the visual and inspirational value the experience provides.
I have fond memories of first hiking it when I was 9, when the last mile across the final basin to the chalet seemed very long indeed. Had we been more clever we would have done the route backwards, or gotten a very early or late start, but instead we went along with the hordes, and M saved the day by hitching back up to get our car, rather than rely on the very overburdened shuttle. First time visitors to the area should by all means do this hike, but should not make the mistake of thinking it will be a lonely experience, or that the extent to which the frontcountry crowds here extend from the road is replicated many other places in the The Park.