Over 200 years ago, the corps of discovery was camped along the coast of present day Oregon and Washington.  While their permanent fort was farther inland, they spent time on the beach, distilling salt from the ocean water, hunting food, and looking at the beached whale.
Today the coast is still ever changing as this website http://www.beachconnection.net/news/002weath_12_05.htm  will illustrate very well. 
To the casual visitor, the beach looks about the same each time they see it.  The rise and fall of the ocean waves gives the illusion of peace and constancy.  What is not seen is the power of the waves, especially during a winter storm.  The sands are constantly being worn away or replaced by more.
The ocean front of both states today is prime property for houses and towns.  But even the sturdiest structure is still vulnerable to the power of the wind, rain and the driven sand. 
A visit to the ocean beach is a never to be forgotten experience.  One of the remotest beaches was reached by a long trail, a mass of driftwood to climb over, and then a smooth beach.  The trail was through an area of rainforest.  This was on the Olympic peninsula of Washington state, somewhat north of where Lewis and Clark had been.
If you can go to the beach, either in Oregon or Washington, be sure to do it.  It is worth the time and trouble to see and feel the power of the never-ending ocean waves.
Cannon Beach, Seaside, Tillamook are all very popular seaside towns, with modern motels, restaurants, and campsites.  An added attraction is a cheese factory in Tillamook.  Visitors can sample various types of cheese.
Beachcombing, kiteflying are a few of the thigs to do on the beach.  Be sure to watch the sun set over the water After all, this is the “Sunset Beach”.