 American settlement of the flanks of the Coast Range did not occur until the early 1840s, at first only marginally.Following the Oregon Treaty the inward flux of migration from the Oregon Trail intensified and the passes and back-valleys of what is now the state of Washington were explored and populated, and it was not long after that railways followed.Despite its being traversed by several major freeways and rail lines, and its lower flanks subjected to major logging in recent decades, large parts of the range remain intense and forbidding alpine wilderness.