I recently participated in an email exchange centering around a possible source for Annie Proulx's choice of the name "Ennis" for her main character. Oregondoggie (a member of this forum) stated that:
"Today, happened to look at The Sheridan, Wyo., County Tour Guide (2006). In it the Bozeman Trail Gallery has a full page ad that includes a pen and ink drawing of an aged cowboy named "Old Man Ennis", an original illustration by Edward Borein (1872-1945) for a book called "The Phantom Bull". [author: Owen Wister.] Google indicates that Ennis ranched in the Madison Valley in Montana. In fact, there is a town there now called Ennis, almost certainly named after him. . . . One could speculate that Proulx saw the drawing in the gallery in Sheridan." The picture is no longer in the tour guide.
A search of Amazon and Barnes & Noble revealed that The Phantom Bull, a short novel, was combined with another novel by the same author, The Pinto Horse, and released as a paperback. The more recent release had all the original Edward Borein illustrations
"In 1927 Owen Wister called The Pinto Horse, the best western story about a horse that I have ever read. The pinto roamed the Montana range in the late 1880s, surviving wolves and blizzards and earning the respect of the herd but never blending in, always standing out in vulnerable perfection. After years of trusting to human kindness, he falls into the hands of fools.
"The Phantom Bull, first published in 1932, is also marked by authenticity and controlled beauty of style. Old Man Ennis, who ranched on the upper Madison in Montana, grudgingly admired the slate-colored Zebu cow, whose wild cunning was passed on to her calf. The calf grows into a monster bull, not personified but endowed with the suggestion of a definite point of view. "A phantom glimpsed against the horizon" is the image he leaves."
The biographical description of "old man Ennis" in The Phantom Bull doesn't quite fit the bio of the historical William Ennis; however, it clearly pinpoints the part of Montana where William Ennis settled and founded the town. According to Names on the Face of Montana (Mountain Press Publishing Company):
"William Ennis was one of the first three men to locate in the Madison Valley. Ennis was born in County Down, Ireland, in 1828. He came to the United States when he was fourteen (1842) and to Montana in 1863. For a while he lived in Bannack, then came to the Madison, where in 1879 he built a store. He became the first postmaster when the office opened in 1881, and for the next eight-six years Ennis' postal service was in the hands of his family. His daughter, Jennie Ennis Chowning was postmaster 1898-1940. In 1873, Ennis took his family through Yellowstone—these were the first white children to see the Park. William Ennis [was shot?] while standing in front of the Madison House in Virginia City—by a neighbor who was angry because of an unfounded rumor that Mr. Ennis had maligned his character. He died of his wounds on July 4th. "
Interestingly, William Ennis, like Ennis in the film version of BBM, had a daughter named Jenny (or Jennie). In The Phantom Bull, however, "old man Ennis" was originally from Texas.
(http://i135.photobucket.com/albums/q135/talkstocoyotes/OldEnnis2.jpg)
This is the drawing of "old man Ennis" that
appeared in The Pinto Horse and the Phantom Bull.