This spider’s common name is Fierce Orbweaver, yet it’s the complete opposite, other than their coloration (or if you are the prey). And oddly, saevus doesn’t translate to fierce, but cruel, which this spider also is not. You can find them across the northern United States and Canada in forests, usually in trees, and in suburban areas in mature plants. The mostly dark gray color and large, board white slash down the abdomen are good identification characteristics. Little information is available on the life history of this species, but it  overwinters in the egg stage with adults found from mid-summer to mid-autumn.
Photo by Gwendolyn Gunn on 8/24/20 near Red Lodge, MT