Custer showed him a different view of that “nature,” on an excursion into land in the northern Plains that had been promised to the Sioux by treaty. Grinnell served as naturalist for that expedition in 1874, an apparent breach of sovereignty that led to a gold rush, and eventual loss of land that the Sioux considered “the heart of everything that is.” Of Custer, killed two years later at the Little Bighorn, Grinnell would write that he “knew nothing about Indians and was anyhow a harum-scarum fellow.”

Grinnell’s own knowledge of three tribes of the Plains — the Pawnee, the Blackfeet and the Cheyenne — would expand with every summer he spent out West. As an author, he was considered the premier ethnologist of these people. But his tone would have made his subjects wince. While advocating for the people of Indian country, while learning their languages, customs and religious ways, and explaining it to the rest of the world, he still sounded like a cultural interloper from Manhattan.

He wrote that Indians had “the stature of a man with the experience and reasoning powers of a child.” This sentiment was common among even the most progressive voices of the time. But when considering the alternative — the plunderers, robber barons and overt racists who tried to wipe the native imprint from the land — Grinnell was ahead of his time. “The story of our government’s intercourse with this race is an unbroken narrative of injustice, fraud and robbery,” he wrote in 1892.

Taliaferro, an author of five previous books, does a good job defending his subject on this count, noting how Grinnell’s attitude evolved from the romantic to the pragmatic. “The tendency is to lump men of his generation and class in one foul ball of bigotry,” he writes.

With his other great lifework, on behalf of the natural world, Grinnell accomplished much. As the longtime editor of Forest and Stream, he went after poachers, pushed politicians to protect the habitat of the creatures his readers loved to hunt, and tried to shame his fellow citizens for what they were doing in the name of civilization. He was largely responsible for the creation of Glacier National Park. And a glacier in those American Alps still bears his name, though it’s shrinking rapidly under the duress of climate change. (Grinnell College, in Iowa, is not connected with him or his immediate family.)

In giving Grinnell his due, Taliaferro, a former senior editor at Newsweek, could have put his manuscript on a diet. There is far too much detail about peripheral matters that do little to enhance the character or his passions. The story often lacks momentum. He is coy — annoyingly so — about whether Grinnell, who married late in life, might have been gay. There’s much hinting of “Brokeback Mountain” intimacy in the great outdoors among manly men of means.

It hurts me as a Westerner to say that Easterners like Grinnell were better stewards of the big land on the sunset side of the continent than many who lived there. Grinnell helped to block a plan by knuckleheads in Idaho to build a dam in Yellowstone National Park. And his fighting words kept the timber, mining and grazing interests from getting total control over our public lands. Grinnell’s memory lives on in the wild. And with this book, he is given the fresh look that he deserves.