This thesis examined the relationships among ecology, economy, and society in the history of Longview, Washington, a planned timber settlement on the Columbia and Cowlitz Rivers. It compared the environmental, economic, and social histories of the Cowlitz Indians, American farmers, and urban industrialists that lived there over the past four hundred years. The central argument of the thesis is that human society cannot separate its economic and social organization from its ecology, nor can it reorder the environment without restructuring its economic and social institutions. Three different groups lived in the same physical space, but since they conceived and used the land differently, their societies developed distinct social and economic frameworks. The narrative of the thesis is chronological, tracing environmental, economic, and social change from about 1790 to 1934. During that time, humans gradually transformed a flood plain once dominated by vegetation and wildlife into a paved, sculpted, and densely populated industrial city. This study outlines the major causes and consequences of that transformation for both the land and its inhabitants. A wide range of source material provided the evidence upon which my conclusions were based. In addition to the more conventional historical sources such as diaries, letters, newspapers, memoirs, maps, and census data, I consulted anthropological studies, geological and geographical surveys, ecological reports, agricultural bulletins, and sociological analyses. My findings are presented in Chapters 2 through 5, with chapter 6 summarizing and drawing final conclusions.

The purpose of this thesis is to study the earliest recorded history of the Cowlitz River corridor, focusing on early exploration and settlement. The importance of the corridor as a major transportation route linking Puget Sound to the north and the Columbia Willamette waterways to the south is emphasized with primary source observations. The study is based on both primary and secondary source materials housed in libraries throughout the Pacific Northwest and Canada. Among the sources include letters, journals, federal documents, periodicals, articles, drawings and monographs.

A flood routing and stage prediction model is developed using the techniques of State Space and Kalman filtering. The governing equation is the physically based hydrologic method of flood routing with the output being an optimal estimate of stage given known inputs of streamflow. These equations are developed in state space and the Kalman filter is employed to estimate the flow and river stage. The model is applied to the Toutle and Cowlitz Rivers in the State of Washington, where the stage is affected by a shifting bed elevation. With the deterministic inputs at Mayfield Dam on the Cowlitz and Tower Road on the Toutle, the optimal output of stage is predicted at Castle Rock on the Cowlitz River. Addition of the Kalman Filter improves stage prediction based on an application to an observed storm event.