In the world of WA state internet fly fishing history, that marked-up-map is like the Magna Carta. Or the Declaration of Independence. I'm picturing it getting stored along with the arc of the covenant in this place:
Worst case scenario it ends up on Antiques roadshow and the appraiser bombs it and deems it useless cos all they're interested in is like hand-carved striped bass poppers, big game reels, stupid wicker creels and atlantic salmon flies.