Linda and I returned a few days ago from the great nation north of Minnesota. We flew to Vancouver, and after a day of exploring that beautiful city, we boarded a train heading for the Canadian Rockies. Trains and buses carried us to Kamloops, Jasper, Lake Louise and Banff, with multiple stops to see the sights along the way. We had a wonderful time: Saw majestic mountains, torrential streams, placid aqua lakes; ate much fresh salmon; walked on a glacier and met some interesting folk. Those who have read some of my earlier columns might guess that riding the rails was a particular high point of the trip for me.

From our first visit to Canada in the 1980s, my impression of Canadians has been that they have a strong environmental ethic — stronger than Americans. On the return from Canada through the tunnel from Windsor to Detroit, the difference in litter and pollution between the two cities could not have been more pronounced. Emerging from the tunnel in Detroit, I was embarrassed and distraught seeing trash and garbage strewn everywhere. The image left an impression hard to erase.

Closer to home in time and place, Steve Lekwa, in his latest column in the Aug. 10 Nevada Journal, laments the trash and garbage left behind on local trails and campgrounds by inconsiderate hikers and campers. In the same issue, editor Marlys Barker decries the spray-paint vandalism in town, particularly the defacing of a patriotic painting in Hattery Park. There are always miscreants who show little consideration or respect for others wanting an enjoyable outdoor experience. I also have seen spray paint defacing on my Indian Creek Trail walks, ruining the natural beauty of the trail.

Reflecting on our Canadian travels, I cannot remember seeing litter or trash on the sidewalks or streets in Vancouver or other cities we visited, and certainly not on any trails or picnic areas in the parks. Wherever we went, recycling was encouraged and used, with waste bins separating plastic, paper and general garbage. Nor did I see any spray-paint defacing except for some railcars in trains or railyards, and even those were far fewer than one would see here in the U.S., where at times almost every car in a train is covered with graffiti.

But as I discovered on this trek, maintaining a pristine appearance does not necessarily preclude deliberate exploitation of a natural resource for economic gain, even though it might be harmful to the environment. A trip highlight was the Columbia Ice Field in Alberta’s Jasper National Park. More than merely a visual experience, we actually walked on the Athabasca Glacier. At the base of the glacier is a visitors’ complex that includes a restaurant, gift shop and other amenities. A staging area is nearby for the special six-wheel buses with balloon tires 5 feet tall, providing rides onto the ice. Specifically designed for the purpose and costing more than one million dollars each, these boxes-on-wheels zip up and down exceedingly steep slopes at the breakneck speed of three miles per hour. The first part of the road to the glacier is dirt and gravel, so to minimize soiling the glacier ice, the wheels drive through a water wash just before driving onto the ice.

As with glaciers across the globe, the Columbia Ice Field glaciers are steadily receding. In the past 125 years, the Athabasca Glacier has receded over 10 miles and lost more than one-half its volume. By the end of the century, no ice will remain. Farmers who rely on glacier runoff for irrigation will suffer.

Inexplicably, tourists’ desire for viewing and experiencing the glacier also hastens its demise.

Along the dirt and gravel section of the road, the buses’ big wheels stir up considerable dust that we could see from several miles away. The dust drifts downhill and settles on the glacier. The ice is clean on the glacier’s far side but becomes increasingly dirtier and darker in color toward the road. So, considering the albedo effect (light colors reflect sunlight, dark colors absorb sunlight), providing tourists access to the glacier and jobs for the local community speeds the glacier’s melting and more quickly deprives future generations of its beauty and water.

In the U.S., as in Canada, exploitation of natural resources for economic development of any kind always comes at a cost to the environment. For example, amenities that promote tourism in the greater Yellowstone National Park region negatively impact wildlife. In 2015, nearly 400 large animals, including deer, elk, moose and bears were killed attempting to wend their way across the maze of roads and highways around Jackson Hole. Even in more primitive areas, the crush of tourist activity frightens animals away from their habitat and blocks migration routes.

An oft-repeated adage in regard to preserving natural areas is “take only photos and leave only footprints.” With the increasing density of visitors to many areas of natural wonder, maybe even footprints are too much to leave!

Pete Korsching is an Iowa State University Emeritus Professor, a Nevada resident and a freelance columnist for the Nevada Journal.