East of Colfax, California, the route of the California Zephyr curves around a mountain at a place called Cape Horn on a ledge hacked out of rock in the 1860s. If you’re aboard the eastbound Zephyr, look out to the right; you’ll see the North Fork of the American River about a mile away and 1,300 feet below you.A century ago, the railroad promoted this canyon view as one of the scenic splendors along its route through the Sierra Nevada. Trains paused here to allow riders to drink it in. Although trains no longer linger at Cape Horn, the view from the window is still the best reason to hop aboard Amtrak.