You can tell FASA was out of Seattle because there is no way in hell there’s any other explanation for why Battlemechs were built in the ass-end of rural Washington.
Battlemechs were built in rural Washington because the capital of the Star League was a giant astroturf metropolis plopped along the coasts of Puget Sound, they chose Puget Sound because Boeing persuaded government officials to put the interstellar capital next to Seattle and the CEO of Boeing was both arrested for and very successful in a variety of crimes as part of this effort.
Did I mention Boeing is still around 1000 years in the future? Yeah that prediction hasn't aged well but it's cool I guess cuz Boeing goes down in flames during a major battle on Earth and their sole extrasolar branch immediately gets nationalized.
Washington is where Boeing is (and they are a huge defense contractor), and Eastern Washington, especially, has long been a place for extremely dangerous military stuff. Spokane went from rural to developed because the government needed a place for a supply line in WWII. The greater Spokane area was where the Handford nuclear plant was, which enriched the uranium for the atomic bombs dropped on Japan and the Demon core. The Umatilla chemical depot was also where they disposed of a bunch of the USA’s chemical weapons stockpile.
I always like pointing out a David Lynch grew up in rural Washington and nearly all his obsessions make sense if you know the region well. Blue Velvet is the perfect treatise on Spokane Washington.
In general, it’s also where a lot of waste from western Washington ends up too.
Eastern Washington and absurd military projects have gone together for over eighty years. So bizarrely this fits.
…But it still totally was because FASA was out of Seattle.
Shadowrun is also set in Seattle, with it's skyhigh rents, high tech industries driving gentrification, increasingly racist police force, and growing social unrest against the federal government.
...written in 1992, by guys working for FASA, in Seattle
Weisman has talked about why he set Shadowrun in Seattle. It came out in '89, before he had lived there.
And as far as I can find, FASA was based out of Chicago.

They may have had some writers/designers from Seattle, but I'm assuming most of them were from around Illinois.
Huh, anytime I've heard about individual writers for SR it's mentioned that they're based out of Seattle (Or are freelancers that CGL was fucking over but that's a different era)
