Is HuntScan Legal in Washington?

Yes, HuntScan is Legal.
We carefully examined the state's regulations. In case you are interested, we highlighted some of the laws.

Hunting with artificial lights (RCW 77.15.450):

Hunting big game with the aid of an artificial light, spotlight, or night vision equipment is prohibited. Night vision equipment includes electronic light amplification devices, thermal imaging devices, and other comparable equipment used to enhance night vision.

Note, HuntScan does not utilize any of the prohibited technology mentioned above, nor does it work in the dark.