I would like a list off all mushroom farms available for sale in the
western united states. What they sale, profitability, location, size,
cost, terms, why they are selling? The more detail the better.

I have searched and searched,and found just one mushroom farm for
sale.It is located in Hansville, WA,  MLS # 29649
           http://seattlelistings.com/farms.htm#    (Scroll down about
half the page)
The price is $334,500. Their stated gross income was $125,293,
operating expenses were $100,000, netting a $25,293 profit.

The next farm has potato cellars, and I don't know if they can be
converted to mushrooms or not, but here is the listing:
                                       
http://www.thefarmandranch.net/prop.asp?number=288&URL=http://www.webcitypress.com/rej/res/welsand1500.html


I also came across some interesting mushroom growing sites you may be
interested in.
           http://www.attra.org/attra-pub/mushroom.html#HowToBegin

This site sells mushroom growing kits that seemingly can be grown
anywhere.(In case a farm is not found !?!)
            http://www.superseeds.com/Mushrooms.htm

Since I could find no more than one actual mushroom for sale in the
western US, I am commenting instead of answereing. PErhaps some other
answerer will have better luck than I. I did find some properties in
Ireland and Canada!

Good Luck!

thanks for the comment, that was the only farm foe sale I could find too.