It’s all here, all in one picture: the great American West. From rolling prairie and bison herds, to modern cities springing up almost overnight, to the Rocky Mountains and the Continental Divide.

These bison are residents of the 15,000-acre Rocky Mountain Arsenal National Wildlife Refuge, land that was once a military arsenal producing chemical weapons during World War II. Despite the resulting contamination and cleanup that followed, wildlife seemed to flourish here, and ultimately a refuge was established. So, sad to say, these bison are not running free on the open range; they are confined to a reserve now surrounded by Denver suburbs, bedroom communities, a soccer stadium, and Denver International Airport.

Maybe these photos grab me the way they do because I’m a product of the Great Plains, used to the vast prairie of Oklahoma, Kansas, and eastern Colorado. I’ve traveled across this country many times on my way from Oklahoma City to the mountains northwest of Denver and back, and it feels like that whole world is compressed into photos like these. I find them absolutely mesmerizing. Skyscrapers erupting from the prairie, with bison in the foreground and mountains behind.

While bison are the biggest occupants, the refuge is home to some 330 different species of mammals, birds, reptiles, amphibians, and fish. All that just 10 miles from downtown Denver. Its 15,000 acres amount to some 23 square miles. But if, like me, you can’t really visualize how big that is, maybe a map will help:

I’ve lived here since 2005 and still haven’t visited the refuge. I’ve skirted it many times but never driven into it. Shame on me; I wouldn’t even have to get out of the car. And where else could I enjoy something like this for free?