Silver, an airline pilot, was casting about for ways to diversify his income and better prepare for retirement.Three years ago, he got an idea.
"I had come home from a trip, sitting on my couch watching CNBC, and I look up and see Jane Wells in the middle of a snowstorm in Wyoming, surrounded by bison." That was February 2011. "I seem to remember the claim was 20 percent growth year over year, over the past five years," he recalled, "I said, 'This is a dubious claim.' "
But Silver was intrigued enough to begin researching.
"I found out it was a true claim," he said, "and it was actually probably a little closer to 25 percent rather than 20."
He met Miller at a meeting of the Diamond Mountain Ranch, and their partnership was born.
"I had no experience with large animals," Silver said. "I don't own any equipment; I don't own any land. So I knew I had to find somebody that was willing to take on a novice rancher and show me the ropes."
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The two wish they had more than their 250 head. That's not enough to meet demand, as they sell to Southern California restaurants such as Green2Go and Pedalers Fork.
Silver and his family spend weekends selling at local farmers markets in wealthy neighborhoods, including Beverly Hills and Calabasas. He said he hadn't planned to become a salesman in addition to ranching and flying, but "then I realized it could be lucrative and help us grow faster."
Growth is hampered by two issues.
First, it costs more to raise bison—especially grass-fed, all-natural bison—than beef cattle. Silver estimates it costs him almost $1,000 a year to raise one animal, or up to $3,000 before it's processed. He sells certain cuts for $25 to $32.50 a pound, however, and profit margins are between 30 and 50 percent.
"Our normal customer is someone who is looking for a healthy product that has a unique flavor, and they are willing to pay a little bit more in order to get that healthy product," he said.
The second obstacle is that there are not enough supply to create a market large enough to affordably put bison on menus nationwide.
The USDA considers bison a "nonamenable species," meaning it does not mandate the meat be inspected before sale. Producers such as Miller and Silver seeking USDA approval have to pay inspectors overtime to get a voluntary stamp (in the shape of a triangle).
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The USDA's upcoming survey may help move the industry into the mainstream and encourage more ranchers to add bison to their herds, though Silver is wary.
"Any time the government is looking at you, you have to be careful," he said.
Regardless, he expects to finally recoup his investment this year, as revenue has quadrupled.
"With my profession, you could literally be one flight away from your last flight," he said of being an airline pilot. "You could have health issues, or if an underwear bomber shows up and tries doing that again, it could ruin the industry."
He sees bison as a profitable and enjoyable hedge, though his wife laid down one rule: "No belt buckles and no hats."
—By CNBC's Jane Wells. Follow her on Twitter: @janewells.