Ranee Mueller wrote:
I live in Washington State, in a fairly warm area that doesn't get as
much rain as Seattle or Olympia, but still coastal (so not the long hot
summers and real winters of Eastern WA). I know we can grow avocado
trees here, but is there any chance we could actually harvest from them?
What would we need to do?

This website doesn't seem optimistic for you, as it marks the northern
limit around Cape Mendocino in northern California. But microclimate
is always important. Another consideration is that you want more than
one tree, preferably of different types, to maximize pollination and
fruiting possibilities. More research needed! -aem

http://www.crfg.org/pubs/ff/avocado.html