REI was started as a buying co-op by a group of friends in Seattle who are outdoor enthusiast for a wide variety of sports. They wanted to purchase equipment at a more affordable price avoiding the high middle man markup. I used to go to one of their early years facilities that was located in a basement space in a building on Seattle's Capitol Hill.
Times have changed considerably. Their concept worked and they kept expanding and are now a chain across the nation with an online presence as well as physical stores. You do not have to be a member to buy but membership does net you discounts issued in the form of buying credits.
The flagship store in Seattle is a real experience, tall outside cascading waterfall. Hand carved wood sculptural features around the entrance. Free parking garage which is very essential in that near downtown area of the city. Not too long ago when I was there on display in the lobby was an adventure oriented travel trailer. They have had several travel trailers on display over the year. But displays change so there is no telling what will be on feature for your visit.
Some items that might be of interest are light weight
cookware, folding chairs, inflatable mattress pads, LED lighting
products, small solar
panels with battery
storage units, etc.