This undated postcard, published by Gopher News Co. of Minneapolis, has the following text on the backside:
A novel attraction is the incline railway at 7th Ave. West and Superior Street. These cable cars connect the downtown section with Duluth Heights. In eight city blocks rise to an elevation 500 feet above lake level from where unusual views of Duluth, Lake Superior, Minnesota Point, and the Duluth Superior Harbor are obtainable.
The incline operated until 1939. More info and similar images can be found on the PDD post “Postcards from Duluth’s Incline Railway.”