I was originally going to entitle my novel either Bowie's Silver or Jim Bowie's Lost Mine. Most of the action in the book centers around a hunt for the famous Texan's legendary mine in reliance on a map that is an obvious forgery to anyone with a grain of common sense. (The map is the novel's "McGuffin," Alfred Hitchcock's term for a device to advance the plot of a story.) The preliminary titles were quickly abandoned, however, because they sounded too much to me like an unimaginative, corny, grade-Z Western.
The title that I eventually chose, The Pirooters, was taken from "piroot," old Texas slang meaning to wander without any meaningful purpose. 
(Some scholars conjecture that the term may be a corruption of the word "pirouette.") The term was introduced to me by J. Frank Dobie, a wonderful historian of Texas and the Southwest who wrote Coronado's Children, a very fine book about Bowie's mine and other legends of lost or hidden Texas treasure. I think that this title suits the novel very well since I basically set out to write The Adventures of Huckleberry Finn on horseback (with the caveat that I am not a patch on the seat of Mark Twain's pants). In both books, the protagonists light out for the countryside and have picaresque adventures with frequent run-ins with venal, grasping, and otherwise flawed representatives of civilization and authority.
Like many middle-aged American men, I have loved Westerns since I was a small child, although more in films than in books. Although no longer as popular as they once were, I nonetheless wanted to write a Western that contained everything I loved about the genre: action, humor, the Western landscape, and a real feel for Nature. The book was also meant to be an extended love letter to Texas in particular and the Southwest in general, a region I have always favored.
I also dislike doing the same thing all the time. Having written science fiction and historical fiction, I wanted to do something completely different and decided on a Western. To illustrate my penchant for variety, after The Pirooters I wrote a humor novel set in the present day and then an alternate history or "steampunk" novel wherein Napoleon invades England.
The chief problem I faced when writing The Pirooters was how to tie together the events that took place in the novel's "present," 1915, with the episodes from 1865 when most of the action takes place, so as to have a satisfactory dramatic conclusion. I won't give away what happens, but I was able to reach a conclusion that, on a personal basis, I found very pleasing. I wrote this novel over the course of a little more than a year from 2002 to 2003.
I have spent some time trying to think of a name for a sequel to The Pirooters. So far, I have come up with The Meanderers, but this just may be flogging a dead horse.