The Tulsa County Library website describes the Sanborn Maps as:
Sanborn Maps are large-scale plans of a city or town, drawn at a scale of 50 feet to an inch. They were created to assist fire insurance companies as they assessed the risk associated with insuring a particular property. The maps list street blocks and building numbers in use at the time the map was made and previous numbers.
Oklahoma's maps are available for viewing (if you have a library card) here. They are a wonderful resource for locating (among other things) streets that no longer exist. So here is the map showing the street layout back in 1926. I marked my grandparents' first home with a red star. Click on the image to enlarge and have fun seeing how the streets in that area used to look.