Robert Cantwell died last week following a heart attack. He was a small man, sturdy and vigorous, with a round, gentle face, a quiet humor and an extraordinary intelligence that enabled him to absorb, interpret and translate into graceful prose vast amounts of information about any subject that captured his fancy.

He was 70 at the time he died, and his curiosity and energy had, if anything, seemed to increase as his years advanced. He was a formidable outdoorsman, in his 60s outriding men many years his junior on the wilderness trails of his beloved Northwest; he was equally content to sit motionless for hours over a chessboard.

His last major story for SPORTS ILLUSTRATED, Bird Thou Never Wert, was a first-person account of an expedition to Mexico in search of the elusive horned guan, a bizarre, turkey-sized bird which Cantwell described as being "velvety-black with bright yellow eyes, its head surmounted by a tall, slender spike the color of ripe strawberries."

Along the mountain trails that eventually led to this rare Seussian creature, Cantwell's rapt readers were introduced to other exotics, such as the resplendent quetzal and the azurerumped tanager, and to the mountain trogons that "often fly in pairs, fast and fitfully in the morning, landing in a tree and taking off at once as though delivering urgent messages to someone hidden in the leaves."

Cantwell, who was born in Little Falls (now Vader), Wash. and greatly enjoyed reminiscing about his first job as a veneer clipperman in a plywood factory, launched his writing career in 1929 with a short story entitled "Hanging by My Thumbs." F. Scott Fitzgerald wrote to Maxwell Perkins, the celebrated Scribner's editor, "In the new American the first work of a 21-year-old named Robert Cantwell. Mark it well, for my guess is that he's learned a better lesson from Proust than Thornton Wilder did and has a destiny of no mean star."

Cantwell published six more short stories and two novels—Laugh and Lie Down (1931) and The Land of Plenty (1935)—that established him as one of the foremost "proletarian" novelists of the period. After the second novel, however, he turned to journalism. He joined TIME in 1935 and remained there, with short stints on LIFE and FORTUNE, until 1945. After the war he devoted himself to nonfiction, writing such scholarly works as Nathaniel Hawthorne: The American Years, and Alexander Wilson: Naturalist and Pioneer, the latter growing out of an early magazine piece for SPORTS ILLUSTRATED, in 1956.

Bob Cantwell was with us during the last 22 years of his life, in which he wrote dozens of memorable articles, among them a portrayal of Cecil Smith, the Texas cowboy who became perhaps the greatest polo player the world has ever seen. When Cantwell wrote of Banjo Paterson, the virtually unknown author of Waltzing Matilda, he made sure that a colorful footnote to history was not going to be lost, at least not to SI readers. As he once said, "History is a natural resource, just as much as fossil fuel. It's what is there. We should not ignore it."

Bob Cantwell was a unique intellectual resource and a friend. We shall miss him.