Map by Jon Knechtel, Pacific Northwest Trail Association
The Pacific Northwest Trail is set to receive official National Scenic Trail designation in an upcoming US House bill, the same designation currently enjoyed by better known trails like the Appalachian and Pacific Crest trails. Admittedly I had never heard of the trail which runs from Glacier National Park in Montana to the Pacific coast of Washington. The 1,200 mile trail sticks close to the Canadian border and currently only about 30 through hikers make the entire trek each year.
The Seattle Times has a great article about the trail and what a National Scenic Trail designation could mean. Various hiking groups seem to be supportive of the idea since it guarantees there will be no logging or development within 1,000 feet (about 0.2 miles) of the trail throughout its entire length.
Based on the map above it *seems* like it should be possible to link up the Pacific Northwest Trail with the Pacific Crest Trail which runs up and down the west coast. Of course the Continental Divide trail runs north and south through the Rockies so perhaps that could be linked to the other end of the Pacific Northwest Trail? Now we just need a southern route across New Mexico and Arizona and hikers could make one 5,000 mile loop! Just plan it so you’re hiking the northern section in summer and the southern section in winter