Could be Washington. https://www.geekwire.com/2015/revealed-how-we-found-amazons-secret-drone-testing-site-and-a-mysterious-satellite-image/ https://www.geekwir

Could be Washington. https://www.geekwire.com/2015/revealed-how-we-found-amazons-secret-drone-testing-site-and-a-mysterious-satellite-image/ https://www.geekwire.com/2015/revealed-how-we-found-amazons-... Meaning, they have tested in WA before.