At the risk of being inappropriate, I consider Rudyard Kipling, Robert W. Service, and the Aussies' "Banjo" Patterson and Henry Lawson to be "manly" poets. Just something about their topics and rhythms....
Add to the list the cowboy poet (there're probably a lot of those) Badger W. Clark. This book is a compendium of two, plus some poems he probably wrote just after the carnage of WWI. Badger writes of The West, Westerners' love of it, and he has a flair for the language, jargon, and, well, just the feel of it all. Many of his poems read as if they were songs, that is, there is an italicized chorus between verses (for some reason I felt those annoying). When he lived, the two most popular seemed to have been "The Glory Trail" and "The Cowboy's Prayer." Old Sixties-era folkies may recognize "A Border Affair,' which was set to music (or paired with an old Irish melody, "Níl Sé Ina Lá") by Billy Simon and revived by Richard Dyer-Bennett, Bob Dylan, and others as the poignant "Spanish Is a Loving Tongue." Good stuff, once.