Washington and Oregan Map Circa 1880's-1890

Antique Washington and Oregan map on reverse side circa 1880-1890.
It is 11 1/2" x 14 1/2".
The maps indicate counties, cities, rivers, lakes, mountains and railroads and other topographical marks of that time period.
Light darkening of the paper and writing in pencil on the edge from prior owner stating the approx year the map was created.
No publisher information listed.
Most likely the map was part of a map book.
Nice!