Michael Portillo heads for the last frontier of the United States, armed with his 1899 Appleton’s Guidebook to Alaska.

Beginning his journey amid the snow-capped mountains and ice-cold inlets of the Kenai Peninsula, Michael finds the golden onion domes of a Russian Orthodox church, along with traditional Russian food and costume and discovers that, 150 years ago, Alaska was a Russian colony.

In Seward, Michael feeds a rescued sea otter pup with a fearsome bite and learns how the luxurious pelts of these endearing creatures were once the most valuable in the world. On a boat trip around Seward Harbour, Michael hears from an indigenous former Alaskan state senator how, shortly before his guidebook was published, the Russian Empire sold Alaska to the United States.

Heading north on the Alaska Railroad past lakes and glaciers and through mountain tunnels, Michael learns what it took to build this epic 470-mile line.