In 1867, William Wilson had constructed the log cabin in which the trading post was housed. Wilson, for whom the creek was also named, was a renegade who roamed the area throughout the 1860s extorting tolls from everyone who tried to cross the Kittitas Valley.
Burch and Splawn hired Martin Davern to haul Wilson's cabin the several miles from its first location to its new location. The cabin measured 14 x 18 feet and was made of cottonwood. Many years later Splawn described this new business venture in his memoir, Ka-mi-akin:
"When we got to unloading our stuff the cabin was so full it looked like there would be no room inside for customers. John Gillispie, a young settler of the previous year and a good friend of mine, rode up and asked how I was going to get inside to do business. I told him I should sell first the goods nearest the door and then gradually work my way in. He said I needed a sign and volunteered to make me one. I accepted his offer. A few mornings later I read over my door, "Robber's Roost." It staggered me for a moment, but, on second thought, I concluded that perhaps John knew more about the sign business than I did. Though it did look very suggestive, I decided to let it stay" (p. 301).The Robber's Roost trading post was initially the only structure in the valley. Settlement soon sprang up around it.
Robber's Roost was an important supply point for settlers and native people, and also for anyone planning to traverse Snoqualmie Pass. Splawn and Burch brought supplies in from The Dalles on the Columbia River via wagon, an extremely arduous undertaking. Nevertheless, they kept the store full to bursting point, and prospered.