If you're panning in Washington State, you have to have the pamphlet of the regulations for panning in your possession. Those pamphlets are your license to pan in some of the streams and rivers where allowed. Those pamphlets are distributed by the WDFW and are designed with regs to protect fish and habitat. I'm not sure, but I think the penalty for violation is up to $5000 and a year in jail. Washington State takes fish and fisheries seriously.