Or even faster, go here:
There is a list of US states on the left side of the page followed by a bunch of countries. Click your region of choice and a further list will be shown of all the affiliates in the area. They’re listed alphabetically rather than by experience or any other rating. From there it is a case of clicking each one and figuring out how near or far they are.
If you don’t want to go through that (it could take a while in California or Florida) then try the links at the top of this thread on crossfit.com
Complete Google Maps of All Affiliates