In the State of Washington archaeological sites are protected, even those on private property. Since 1974 it has been illegal to knowingly disturb archaeological sites or resources on private or public property without a permit from theWashington Department of Archaeology and Historic Preservation (DAHP). The 1974 Archaeological Sites and Resources law protects all prehistoric sites and any historic properties abandoned for more than 30 years. Civil penalties as well as the costs necessary to investigate and restore the disturbed archaeological site can be imposed and any resulting artifacts can be seized.
Private land owner have a number of rights. Artifacts that are legally discovered on their property (either as individual finds or as part of a legally permitted archaeological survey or dig) belong to the land owner. Archaeological sites discovered on private property cannot be legally registered without the permission of the landowner. If the private property owner chooses to register their site there are incentives available to the landowner such as tax breaks, easements, and open space designations.
Since 1941 all bones and artifacts within Native American graves and unmarked burials have been protected. The 1941 Indian Graves and Records law prohibits knowingly disturbing graves and makes such activities a class C felony. This law also prevents the sale of any grave goods or human remains removed from such graves. The inadvertent disturbance of graves requires reburial with the supervision of the appropriate Indian tribe.
The full list of Washington State laws affecting archaeological resources is available through the WA DAHP website.
Thanks for finding the proper references jaz. Looks like it is probably okay to keep, inquire about, etc. But I imagine a Tribal or Fed lawyer could figure out some way to mess everything up. The “knowingly” part. “Did you ever come across artifacts before? You did? An arrowhead!!?? And yet you decided to dig MORE post holes!!!???”
I think a variation of “shoot, shovel and shut-up” is perhaps the wisest choice. Tell the story when you pass it down to a child/ grandchild once they are older.
Plus - do your OWN research on what the artifact is, the tribes in the area, etc. If it seems to be an unusual find and noteworthy - then perhaps consider approaching a museum. And perhaps contact a lawyer first.