The wind started blowing at two in the morning. Branches and leaves ricocheted off the tent, and the trees around Diggity Stream groaned. I barely slept as gusts burst off the lake and rattled the tentpoles. When I finally got up, it was 5:30 a.m.

Fog flowed from the mountains into Spednic Lake. The eastern sky was an arc of amber light. Wind roaring through the trees was thick with the dank scent of lake water turning over. Northern Maine gets cold in early October, and I had spent most of the night shivering beneath clear skies and a swirl of stars. The Milky Way ran exactly over the middle of the campsite, perpendicular to the stream. The last thing I saw before falling asleep was a shooting star splitting the sky in two.

This was day three of a 4,000-mile journey along the United States-Canada boundary. I grew up in northern Maine and had always been fascinated with our “forgotten border.” At 5,525 miles, including Alaska, the northern boundary is the longest land border between two nations in the world. Most of the eastern third of the line runs along rivers and lakes, like Spednic, so the best way to see it is from the water. With all of the news about growing tension along “the world’s friendliest border,” I thought it would be interesting to travel along it instead of cross it.