Scarpa's Summit boots ($280) are serious footwearwaterproof leather with a Gore-Tex liner, thick rubber rand, tough midsole for support, and more.
In short, they will go just about anywhere. They'll eat a Rainier climb for lunchthey're perhaps even overkill for a summer climb. And for just about any Pacific Northwest glaciated peak, they're more than adequate.
The down side? They're awfully heavy (4 pounds, 6 ounces for a pair), and a bit on the stiff side. So while they're an okay trail boot, they aren't great. So does that mean you should stuff them in your pack and wear something lighter? There is some sense to that. The conventional wisdom is that a pound on your foot costs you more, energy wise, than two on your back. But I wouldn't do that on Rainier. You'll be on snow not that far from the parking lot (assuming you take one of the standard routes with Paradise Lodge as a start point) and will feel silly changing out footwear.
For most other climbssay, Glacier PeakI'd probably lug the Summits in a pack and wear something much lighter on the trail. That's probably a good policy, in fact, for just about any peak that requires an approach hike of eight or nine miles or more.
Happy climbing this summer! You'll like the Summits. Scarpa boots are first-rate.