Arcadia and Hug Point State Parks both lie just south of Seaside. Both feature beach access for checking out shorebirds.
Further South is Neahkahnie Beach which also provides beach access for shorebirds.
Just North of Tillamook is an access to Nehalem Bay State Park. The spit enclosing Nehalem Bay gives shorebird birding alone one side and a sheltered bay on the other for wintering ducks and loons as well as gulls, grebes, and herons that can be seen year round.