St. Peter's Cathedral is the seat of the Episcopal Diocese of Montana, and it occupies a prominent position in the downtown streetscape. The building is in a Gothic Revival idiom but on a more modest scale than the Catholic cathedral a few blocks away — which makes it, if anything, easier to absorb. The stonework is carefully done, and the setting among the downtown streets gives it an urban presence that larger suburban churches lack.
The cathedral dates to the late nineteenth century, when Helena's Episcopalians — many of them drawn from the eastern establishment families that moved west in the boom years — wanted a church that reflected their standing. It's an active congregation today, and visitors are generally welcome outside of service times. If you're already walking the historic district, it's worth a brief stop: the interior has good stained glass and a quiet that the surrounding streets rarely offer.