Half the fun of touring Alaska's vast Denali National Park is spotting wildlife such as bear, moose, caribou, wolves, mountain sheep and soaring eagles in their natural wilderness habitat.
Now there's a new attraction: dinosaurs - well, at least their tracks and footprints, estimated at around 70 million years old.
But they are nowhere near as visible for the public as, say, relics 20 million years older now preserved inside a large structure near Winton in the Queensland Outback.
And so far no dinosaur bones have been unearthed in five years searching in the park although fossilised remains have been reported in northern Alaska's North Slopes area since the mid-1980s.
Researchers in the last two summers have found new tracks, plant fossils and the fossil traces left by insects moving through mud and evidence of birds feeding, says Kris Fister, public affairs officer for Denali National Park and Preserve.
Also discovered were tracks from prehistoric wading birds.
While most of the Denali tracks are in remote areas, the first one found in the park, in 2005, is on display in a dinosaur exhibit at the Murie Science and Learning Centre near the park's entrance,
"We removed this track because it was located next to a large creek where it possibly would have been damaged and/or eroded by the water," said Kris Fister, adding that there were no plans to bring other tracks in for display.
"Some are readily accessible from the park road via a steep two-mile (3.2km) hike and we have taken groups to the sites during seminars and school field trips from the Murie Centre," she added.
It's possible for visitors to see them, if they know what they're looking for. There are no signs pointing them out as the sites are not on developed trails and are in the wilderness areas.
Found in the Igloo Canyon and Double Mountain areas of the six-million-acre park have been many tracks of theropods - meat-eating dinosaurs which walked on their hind legs - and some of hadrosaurs, or duckbilled dinosaurs on which the theropods were thought to have preyed.
So many high-quality preserved tracks have been found, measuring up to 50cm by 50cm, that paleontologist Dr Tony Fiorillo of the Dallas Museum of Natural History refers to them as cretaceous dance floors.
The train journey to Denali from Anchorage (380km) or Fairbanks (190km) is a fascinating experience in itself as passengers enjoy the awesome scenery and native fauna from the comfort of their scenic-dome carriages aboard the McKinley Explorer, where two diesel locomotives haul a total of 23 cars.
In the town of Denali, there's a wide choice of accommodation (we stayed at the McKinley Chalet Resort) and also of coach tours, lasting from three to 12 hours viewing rugged mountains, the tundra, coniferous taiga forests, rivers, lakes and fertile valleys plus 40 species of animal and 175 types of bird.
Coaches traverse the 150km park road but there are restrictions on where private cars may travel.
Driver-guides, expert in wildlife, geology and history, can spot bears feeding in bushland 250m more from the road; he or she stops the vehicle for passengers to focus their binoculars and zoom lenses; and may also shoot the scene on a videocamera then play the tape in close-up over the coach's TV screens.
The mountain vistas include, for the lucky ones, glimpses of Mount McKinley, North America's highest peak at 6,194m - if it's not shrouded in mist.
Apart from moose and other large animals there are some interesting smaller types such as the snowshoe hare (named for its large furry paws which turn white in the winter), little rock rabbits, beavers and, squirrels.
Rafting on both mild and wild rivers is also available, as are flight-seeing, dog-sledding and fishing.
The train experience is enhanced should you have a jolly car manager such as Diann (Diann) Kirkwood, a former teacher from Texas, who mixes commentary on the passing wilderness with good-humoured stories on Denali, past and present.
Diann's talk begins with a cheerful safety lecture not designed to calm any nervous passengers: In an emergency you pull a handle to open the window then jump two storeys to your death. Wives go first to provide extra cushions to land on.
She told how at the completion of the Fairbanks-Anchorage railway ailing US President Warren Harding was to hammer in the last golden spike linking the tracks and, allegedly, had been over-treating his illness with whiskey and missed the spike completely the first time.
(Mr Harding, 57, died from a heart attack soon afterwards in San Francisco.)
Another tale described how the railway company once banned motorists from using a railway bridge over the Nenana river to save them a near-15km drive to the nearest road bridge; the dispute was eventually settled, but to this day local motorists show their displeasure at the company by mooning passing trains every July 4 Independence Day.
One man also once did a full frontal as well, Diann said. But last year it was raining and only three mooners showed up.
The Denali Park summer season usually runs from about mid-May to the third week in September, but the tourist industry does not completely go into hibernation, like the bears; the park has a winter program with cross-country skiing, dog-sledding, snowshoe walks, winter cycling, snow sculpting, history talks and science-based activities.
Late September summer offers other bonuses such as the spectacular Northern Lights (Aurora Borealis) and also the reds and yellows of the autumn foliage.
IF YOU GO
Many summer cruise packages to Alaska from Vancouver and Seattle include visits by train to Denali National Park. Contact Travel The World for details of Holland America Line cruises.
For Alaskan holidays visit the Alaska Travel Industry Association.