Surrounding the area, however, were lush spruce woods and fertile Prairie farmland.
"These were unexplored but most thrilling mysteries, sure to offer new kinds of life -- birds and beasts. And like everything in the world about me they were full of promise, full of joy," Seton wrote in his book Trail of an Artist Naturalist.
Today, the area is known to many Manitobans as the Carberry Desert, or Spirit Sands Desert.
But the scene is much different than the one that greeted Seton.
Mixed-grass prairie and trees such as cottonwood, spruce and birch have slowly encroached on the dunes, leaving just four square kilometres of what was once 6,500 square kilometres of open sand after Lake Agassiz dried.
The area is also, in fact, not a true desert.
Its annual rainfall is almost double the 250-millimetre limit for desert status.
The climate, combined with an aquifer underneath the sand, allows the trees and grass to flourish.
Still, Spirit Sands remains the subject of fascination for locals and tourists alike, who flock to Spruce Woods Provincial Park each year to take in the desert-like attraction as well as camping, hiking and canoeing down the Assiniboine River.
For those not inclined to hiking up the sand dunes, which can tower up to 30 metres, Larry Robinson offers a unique perspective from his covered wagon pulled by two Belgian Geldings.
Robinson, a meat cutter by trade, bought Spirit Sands Wagon Outfitters eight years ago.
He takes about 20 visitors at a time on a 90-minute, bumpy, up-and-down adventure as the wagon creaks first through thick woods, then a clearing spotted with circular juniper and wolf willow, until finally he makes his first stop at the dunes.
The inclines are short but steep and children especially can delight in losing their footing in the shifting sand as they race up and down each dune. Their parents, some trailing behind somewhat winded, marvel at the sharp visual contrast of the woods and grassland behind them and the sandy hills ahead.
"It's a great way for people to see this kind of thing who wouldn't normally be able to walk the whole way -- older people and kids," Robinson says during the break.
The tour also includes a stop at Devil's Punchbowl, a large pond-sized depression formed as sandy riverbanks collapsed due to erosion from small underground springs that once flowed directly into the Assiniboine River about 500 metres away.
Robinson says the bowl gets its name from the fact the early pioneers couldn't figure out where the open water that trickled during the frigid Prairie winters was coming from.
Throughout the tour, Robinson shares many anecdotes he has picked up from aboriginal friends and customers about the traditional uses for many of the common plants, trees and flowers along the tour.
Everything from diapers to insect repellent and sunscreen can be gleaned from the nature around the park.
Kelly and Lorie Martel of Winnipeg leave the tour impressed to have found such a unique landscape in their own backyards.
But they caution expectations should be kept within the context of the province's geography.
"If people come expecting the Sahara (Desert) this is not it," said Lorie Martel.
"But it's definitely a desert because of the rolling sand dunes, it's similar to me to the (Alberta) Badlands," added husband Kelly.
Park interpreter Madelyn Robinson says she often has to correct visitors' misperceptions that the area is a true desert.
"We still have people say, 'It has to be a desert, look at all the sand, look at the cactus,' " said Robinson.
"It depends on what your definition of a desert is but this doesn't fit the scientific one."
Robinson and other interpreters offer guided walking tours of the dunes and surrounding ecosystems throughout the summers.
She says the area was named Spirit Sands because several aboriginal groups, such as the Cree and Ojibwa, historically travelled through the area each year to follow the bison. Some would also go on vision quests because their creation story stated man and woman came from the sand.
As for the future of the dunes, Robinson says it's likely they will slowly disappear as they run out of room to shift.
"There's really not a lot that could be done, it would be very expensive (to preserve)," said Robinson.
"But we do have a management plan where we're trying very hard to save the prairie within it because the Aspen -- which we call the pirates of the prairie -- will eventually take over."
-- Canadian Press
Visiting Spruce Woods
The park is located about 175 kilometres southwest of Winnipeg. Follow the Trans-Canada west, then take Highway 5 south at Carberry and follow the signs to the park and dunes. Spirit Sands Wagon Outfitters operates from May through September. Prices are $9 adults, $6 youths.
* Parks Manitoba 1-800-214-6497, www.manitobaparks.com
* Spirit Sands Wagon Outfitters (204) 827-2800;
* Dusty Mile Outfitters (204) 822-2853.