The cathedral is a
Gothic Revival structure that follows a
basilican plan without side aisles. It is composed of local volcanic
tuff that is rock-faced,
rusticated, and
ashlar in regular courses. The main
facade is flanked by two towers of equal height that are capped with octagon-shaped
spires and crosses. A
rose window is located in the middle of the main facade above the double entryway. The main
nave features three pointed-arch windows on each elevation between
buttresses on the exterior. The
transept has two larger pointed-arch windows below a rose window on both elevations. Two more pointed-arch windows are located in the apse. The rectory, which also served as the bishop's house, is composed of volcanic tuff, and it is laid in the same manner as the cathedral. The 2½-story structure is built on a raised foundation. It features a
gable roof with
dormers and a front porch. A garage was added on the west side in 1960. The former chancery building is composed of volcanic tuff like the cathedral and the rectory, but it is randomly laid and it does not have the proportion of the other two. It is capped with a flat roof, and its windows and hardware reference the era it was built. ==Renovations==