Any luck with this? I can't help you, but I had the exact same thought. Longmire really does push Rainier. Back in 2018, Pabst told me that Rainier was only available in these states: Washington, Oregon, Montana, Alaska, Idaho, Wyoming, Colorado. You have to email Pabst, but if visiting these states they can give you store locations that carry the product. Just a little help if you travel west in the future.
I can't help ya, but I live in Morgantown, WV, so if you ever wanted any of our local brews from down south let me know, because id love to try a few Pitt local brews!
Rainier is found absolutely everywhere in Washington state. Dive bars, gas stations, convenience stores, grocery stores, etc.