This route in Glacier National Park can be done either direction but I think the views becoming increasingly more dramatic starting from the Bowman side.
Starting at the Bowman Lake campground, hop onto the trail towards Head of Bowman Lake Campground/Brown Pass/Hole in the Wall. The trail starts with a beautiful seven mile stretch along the length of Bowman lake. Continuing on, the trail starts to slowly climb towards Brown Pass with most of the elevation gain in the last two miles up to the pass. From the pass, there is a beautiful view of the backside of Thunderbird Mountain, Lake Frances and the Porcupine Ridge.
Taking the left junction in the trail towards Hole in the Wall leads to what might be the best section of trail in Glacier. The trail winds around a beautiful cirque overlooking Hole in the Wall Falls with great views of Boulder Peak and Mt Peabody beyond it. The climb up to Boulder pass crosses some nice boulder fields and the view extends up to Canada from the pass.
A worthwhile variation is to scoot from Boulder Pass up the scree field and to the top of Boulder Peak. There is a stone slab throne on top which offers amazing views of Kintla Peak, Kinnerly Peak and the Agassiz Glacier. Just a stunning 360 view of Glacier and up into Waterton
Descending down from Boulder Pass is straight forward, with enough switchbacks to quickly drop in elevation. About a mile or so of the trail is decently overgrown, so take extra care with footing.
Dropping upper Kintla Lake means all the hard parts of the route are over, and it's just a chill 11 miles to the foot of Kintla Lake.
https://www.backpacker.com/trips/glacier-national-park-bowman-lake-to-kintla-lake
http://enjoyyourparks.com/boulderpassglacierpark.html
