Alaska's big-name wilderness spots are scattered far apart, which is why Princess Cruises built its whole Alaska operation around "cruisetours" — a cruise along the Southeast Alaska coast stitched to an overland trip into the state's interior. The line runs 28 of these itineraries (more than any other operator), lasting from 10 to 17 nights, and it owns its own wilderness lodges near the parks plus a fleet of glass-domed railcars and motorcoaches to move guests between them. No other cruise company has that level of infrastructure in Alaska.

The flagship is a 17-day escorted tour that covers four of Alaska's eight national parks in one trip: Denali, Glacier Bay, Kenai Fjords and Wrangell-St. Elias. Guests spend two nights at each of Princess's five Alaska lodges, including the Kenai Princess Wilderness Lodge on the Kenai Peninsula and the Copper River Princess Wilderness Lodge near the state's least-visited giant. The cruise leg adds Glacier Bay plus a stop at Skagway, whose gold rush district sits inside Klondike Gold Rush National Historical Park — five national park sites in total. Depending on whether you cruise or tour first, the ship swaps Hubbard Glacier for College Fjord.

A 15-day version focuses on Kenai Fjords, a park nearly the size of Rhode Island that's home to the huge Harding Icefield. Three nights at the Kenai Princess lodge leave time for glacier viewing by boat, kayak or flightseeing, salmon fishing on the Kenai River and wildlife spotting — think humpback whales, puffins, Steller sea lions and black bears. The trip also includes three nights near Denali, two in Fairbanks and a seven-night cruise through Glacier Bay.

For a taste of a park most Americans can't even name, the 13-day tour includes an overnight at the 85-room Copper River lodge, which looks out over the Wrangell Mountains and the Trans-Alaska Pipeline. Wrangell-St. Elias is the largest national park in the US at more than 20,000 square miles — roughly six times the size of Yellowstone — yet draws under 100,000 visitors a year. From the lodge you can hike, raft, ride ATVs, take jet boat tours or visit the ghost town of Kennicott, a former mining camp.

Meals are included on the land portions of all three tours. The season is short — May to September only — and departures are limited, so operators suggest booking 10 to 12 months ahead. June and July bring up to 18 hours of daylight; July and August are best for whales and bears; May and September are quieter and often cheaper.

If you want one holiday that covers Denali, Glacier Bay and the lesser-known parks without juggling separate bookings, these tours are among the strongest ways to do it — best suited to travellers with a week and a half or more to spare.