The Indians perform [the task of splitting cedar] by means of little wedges, and manifest a good deal of dexterity and skill; for, if the wedges are not placed properly, the board will be full of twists and creeps.
— James Swan, 1857
Archaeological evidence along the Northwest Coast shows that Native people have had the the technology to obtain and shape huge timbers for house building for at least 5,000 years. Such massive timber woodworking became commonplace 2,500 years ago.
The native Western red cedar was ideal for building plankhouses. This strong, light, rot resistant wood grows to 230 feet high and 14 feet in diameter. It can be easily split into right-sized planks, approximately 20 feet long, two to three feet wide, and two to three inches thick. To split the wood, the Chinook used hemlock and crabapple wood wedges driven with hammerstones or mauls, a system that made it possible to gain multiple planks from a single tree. Native builders used adzes and celts of stone in combination with fire to fell large trees for plankhouse poles.
Despite cedar’s rot resistance, the Chinook replaced all of the planks and posts roughly every 20 years due to wear and tear. Evidence indicates regular replacement of planks at both Meier and Cathlapotle, where Chinookan peoples lived continuously for many hundreds of years.