It is up just before you cross the river to the Salmon la Sac campground. A bit of a drive from I-90.
That is only between Harborside Drive and Port Industrial Boulevard on 37th Street. Once you cross Port Industrial there are a bunch more tracks. https://www.google.com/maps/place/G...8b03c9b9eaecc1!8m2!3d29.3013479!4d-94.7976958