 The northern portion of the district, between 15th Street and 21st Street, has been zoned with Historic Preservation Overlay Zoning by the City of Tulsa and is called North Maple Ridge.Maple Ridge Historic District (MRHD) was the first Tulsa neighborhood to be listed in the Oklahoma Landmarks Inventory.It was placed on the National Register of Historic Places on April 6, 1983, under National Register Criteria A and C. Its NRIS number is 83002138.