Hi Cozycamper,
I did some research and made some phone calls around the Olympia, WA area (within about 25 miles) and these are the better options and possibilities in the area that I’m aware of (not just for memory foam). I also listed the brands they carry that the retailers told me they could provide the specs of their mattresses so that you can make meaningful quality and value comparisons.
http://www.mattressdepotusa.com/ Olympia, WA (and other locations). Easy Rest (memory foam), Restonic (latex hybrids, gel memory foam, and innersprings), Lady Americana, and they also have an all Dunlop latex Englander that is not listed on their site. They told me that they would try and get foam specs from any of their reps but that Restonic and Easy Rest would be the most likely.
http://mattressranch.com/ Olympia, WA (and other locations). They carry a full rage of Lady Americana mattresses including latex hybrids, gel memory foam, innerspring, and microcoils. they told me they will call the factory for specs on any of their mattresses.
http://rosesfurniture.net/about-us/ Centralia, WA. They carry a line of mattresses made by NWbedding in spokane which includes latex, memory foam, and innersprings and will also call the factory for specs
http://www.holylamborganics.com/ Oakville, WA. They carry a range of high quality organic latex, innerspring, and cotton / wool mattresses including WJ Southard and toppers that they manufacture themselves. Some very good quality here and knowledgeable people but they are also in a more premium budget range.
There are also some good options north of you in the Seattle/Tacoma area listed in post #2 here and south of you in the Portland area list in post #2 here.
Hope this helps.
Phoenix