Just when you thought the old formula Westerns were getting to be about as tired as a team of oxen crossing Death Valley, a new Western hero comes to the rescue.

Hank the cowdog, the latest hero for young readers.Hank, head of security at a Texas Panhandle spread in Ochiltree County, earns his keep protecting the ranch from such villainous creatures as dog-killing coyotes, egg-sucking foxes and a one-eyed killer stud horse.

In the 12 books chronicling his adventures, Hank the cowdog solves myriad ranch mysteries while engaging in such traditional canine pursuits as barking at the mailman, chasing a winsome collie named Beulah and sleeping in his gunnysack bed.

The cowboy canine is the creation of author and ex-cowboy John R. Erickson, who has sold more than 200,000 Hank books since 1983. The latest, "Hank the Cowdog: The Fiddle-Playing Fox," was published in February by Texas Monthly Press. The 13th volume in the series, "Hank the Cowdog: The Wounded Buzzard on Christmas Eve," is scheduled to be out this fall.

"I don't mind working for a dog," joked Erickson, 45, whose scholarly manner is a far cry from his protagonist's homespun character.

A former Harvard Divinity School student who quit his studies just three hours shy of a master's degree, Erick-son spent 15 years having his historical novels rejected by New York publishers, then turned to writing for the San Angelo-based Livestock Weekly magazine.

"I ran out of ideas and I did a story about a dog, which I thought would be fun," Erickson said. "I picked a dog named Hank who belonged to the neighbors and who I had known when I was ranching up in the Oklahoma Panhandle."

Hank's popularity has spawned audio tapes, a Hank fan club, T-shirts and posters. The first Hank book was made into a 30-minute cartoon on CBS television's "Story-break" series. Erickson even publishes a catalog of Hank spinoffs, including two volumes of "Hank the Cow-dog's Greatest Hits."

Supplementing the books with audio tapes appealed to Erickson because his writing style is heavily influenced by storytelling.

"One of the major tasks of a young writer is to find the voice he's most comfortable with that can express what he wants," he said. "I tried on a lot of voices before I began imitating the way the cowboys told stories. That's when my stories really began to click."

Erickson uses a folksy, conversational style in the tales, all told by Hank himself.

Some of the cowdog's zany adventures are inspired by the author's own cowdog, a blue heeler named Sophie, as well as the antics of his three children.

"A lot of those Hank episodes come from experiences that I've had or seen on ranches," he said. "Some of them come from my observations of dogs. I grew up with dogs, and I used to sleep, eat and play, do everything with my dog."

"The original Hank audience was all adults, but somewhere along the line that changed," he said. "We didn't do anything different."

Erickson no longer worries about running out of Hank plots.

"It's great fun writing the Hank stories," he said. "I'll go on writing them as long as I'm having fun. I don't ever want it to turn into a job, because I think the strain would show."