The stories in Thomas McGuane’s most recent book of fiction, 2006’s Gallatin Canyon, are portraits of wide-open spaces—Montana and Key West, usually—that are defined by their spareness, their dry humor, and their unflinching observations of relationships going bust. He makes it look easy enough, but no American author may have worked so hard to achieve that calm simplicity. Early novels such as 1973’s Ninety-two in the Shade are as fake and gunk-filled as cans of spray cheese; his showy, Faulkner-goes-gonzo style made him a fellow traveler in the world of Terry Southern–esque satirists, but it’s aged poorly. A decade later he’d begun scraping away at all that ornamentation—1984’s Something to Be Desired, in fact, follows a ne’er-do-well Montanan rehabilitating himself through hard work—and by 2002’s The Cadence of Grass there’s barely a useless adjective to be found, so deeply has he concentrated on mapping the fault lines that emerge in a Montana family after the death of its patriarch. Yet McGuane remains an essentially satirical writer: His plots echo the old saw that when man plans, God laughs. The heroine of The Cadence of Grass enters a roadhouse looking to hook up only to wind up with a conspiracy nut, escapes but winds up stuck with a snowed-in family with a grandpa waiting to be cremated; the hero of Gallatin Canyon’s centerpiece, “The Refugee,” sails to Key West in the hopes of detoxing and ridding himself of bad memories, only to find a new set of humiliations. McGuane steers clear of the Mississippi, but he’s Mark Twain’s inheritor all the same; he speaks tonight as part of PEN/Faulkner’s reading series. McGuane discusses and signs copies of his work at 8 p.m. Friday, Jan. 18, at the Folger Shakespeare Library, 201 East Capitol St. SE. $15. (202) 544-7077.