Hey Doc,
I think the name of the railroad your great grandfather worked on was in Sanpete county, located in central Utah. It was variously spelled San Pete and San Pitch, after a local Indian. The San Pitch river runs north through the area. My ancestors from Denmark settled there in 1860. My dad lived across the street from that raliroad line in a little town named Moroni, where he grew up and met my mother.
By the way, this is my first post on the forum. I'm glad to be here.
Regards.