The Power of the Dog

No book-club edition is documented in the sources consulted. The dominant "first thus" trap is the 2001 Back Bay Books reissue (Little, Brown's paperback imprint), 293 pp, ISBN 0316610895, which adds an afterword by Annie Proulx; the Proulx afterword is hosted on Little, Brown's and Hachette's own sites, confirming its 2001 origin. Any copy containing the Proulx afterword is post-2001 by definition and is not the 1967 first.