Louis Olson, also known as Louis Gunderson, was lynched in Olga, Cavalier County’s largest city. Olson was said to have murdered Susan McEwen at her homestead shack by Rosa Lake. Before the four special constables could take Olson to the county jail in Pembina, a crowd of angry Rosa Lake folks showed up. This mob of supposed justice-seekers somehow managed to pull Olsen from his constable escorts and, with rope in hand, headed to a nearby grove of trees.
From Dakota Datebook