CAVE CREEK, Ariz. — From an improvised pulpit nestled on a slice of desert sand between a bull-riding ring and a bar serving biscuits and $3 beers, the preacher opened his last sermon of the year with a question and a revelation.

“How many of you have ever been a suspect in a murder case?” he asked, his blue eyes scanning a small flock of congregants huddled around a pile of burning logs. “I have.”

Steve Gilbertson, 52, has been a preacher for about 30 years. Four months ago, he started a church of his own. At his last job, he had led an informal Sunday morning service over coffee and doughnuts at a local megachurch. Now he preaches under a mesquite tree, in the shadow of a saloon best known for the quality of its country-western bands and the fervor of its regulars’ allegiance to the Green Bay Packers.

The saloon is called the Buffalo Chip, and the church it houses, officially named Ecclesia, is informally known as Church at the Chip, or cowboy church. Mr. Gilbertson and the saloon’s owner, Larry Wendt, met several years ago at the church where Mr. Gilbertson worked and that Mr. Wendt sometimes attended. Mr. Wendt remembered asking him to come by on Fridays to say a prayer before bulls and riders took to the ring, on the edge of a knoll punctuated by saguaro cactus. When he heard Mr. Gilbertson needed a place for his church, he offered him space at the saloon.