Went through the same thing last summer. My old tires were worn and popped a hole up on the gravel road. Needed something with a nice thick tread as I've popped a few on that road.

I checked Craigslist, Ebay, dealers, and on-line warehouses.

There's some junk yards or places that specialize in used tires especially from Tacoma to Everett. They list on Craigslist. Could also buy re-treads for cheap on Ebay.

Just do your homework and you'll figure it out.