Cowlitz county lies immediately north of Clarke county, bordering
about 40 miles on the Columbia river. It has about 1,100 square
miles of territory, and about 13,000 people. The southwestern portion
is largely composed of level valley lands, while its northeastern
part is occupied by the foothills of Mount St. Helens. The drainage
is all westerly and southerly into the Columbia river. Cowlitz river
is navigable as far as Castle Rock, and is an important factor in
the transportation problem.