In Montana the answer is yes as long as there is legal public access. I believe this is also the case in Washington and in many cases the land is overseen by the WDFW. There are also parcels that are leased and developed(like some DNR parcels) and there could be restrictions based on safety on some of these parcels. BigTex can you confirm this?
All BOR lands in WA are open to hunting, with the exception of the obvious areas like campgrounds, dams, and other "developed areas."
A large majority of BOR lands are BOR owned but managed by WDFW as "Wildlife Areas." In fact, most WDFW "Wildlife Areas" in Grant County are actually BOR lands.
Regarding the BOR lands leased for agricultural purposes, per BOR those lands are still open to the public for hunting. Now will some farmer get pissed seeing somebody walk through "his" apple orchard and cause a fuss? Yes, but per BOR those lands are open. WDFW and BOR have been working for the past year to inform their leases of the hunting "issue," so not all of them may know about it at this time.