Pit was opened in 1923 and closed in 1951. I'm still looking for the yard map for the gravel pit.
Note how the adjacent NP tracks are labeled. The one closest to the pit says "N.P. Ry." and is the line down from Coulee City, that connected with the GN siding. The other line says "Connell North Line" and is the one built north from Connell. You can see the junction at Adco for those 2 lines.
Better view of the area can be seen here.