You are right, the name of the street is Sortman Avenue and it is in Duboistown, Lycoming County. Duboistown is just a small community outside of South Williamsport. For many years there was a gas station on the corner of Valley Street and Euclid Avenue called Sortman's. It used to be owned by a Sortman family before my time. My parents don't live far from there and I will ask them is they remember the names. I also went to South Williamsport High School with a Jim Sortman who was related to them. I think my Mom told me that he is a now a district magestrate in the local community.
The City Directory of 1892 lists John H Sortman, engineer, Valley Road, Duboistown and Harry C Sortman, laborer, Mosquito Valley Road, Duboistown.