Population in the tiny town of Ralston in northwest Wyoming swells ten-fold for a few days each June.

It's all about mules. It's always the week of Father's Day.

Events begin Wednesday, June 13 and last through Sunday, June 17. It’s the 15th anniversary edition of Jake Clark's Mule Days to roll through Ralston, seven miles west of Powell in Park County. Mule Days brings crowds of up to 1,500 to the hamlet, which is home to a population of scantly over 100 for the rest of the year.

The Mule Days Rodeo at 1 p.m. on Saturday, June 16, and the live auction of select saddle mules at 1 p.m. on Sunday, June 17, are the big events on the five-day card. Clinics and competition in mounted shooting, team sorting and ranch mulemanship, along with jackpot team roping and barrel racing, extend Wednesday through Friday.

Mule Days has literally put Ralston on the map. The aficionados of mules come from all over the country to bid in what Jake Clark proudly proclaims "America's finest select saddle mule auction."

Jake's wife, Kay, recalls the time she fielded a telephone call that illustrates the mushrooming reputation of the Ralston event and the caliber of the clientele.

Just a few days ahead of the event, she took a call in the office from a potential auction buyer who had heard of Mule Days and was very interested in getting a mule. When Kay offered to take a phone bid, the lady on the other end of the line declined.

"She said they would just fly out in their plane from Washington," Kay said.

That's the following that has come to know Mule Days as the premiere showing of fine quality mules, fetching prices higher than any other mule industry auction in the nation. The June 17 auction will offer 110 head for sale, all personally screened by Jake Clark.

Jake is a Wyoming born outfitter who has used mules as mountain pack and riding animals for more than 40 years. Jake began using mules as his riding animals when he noticed that he could use the mules day after day, while he needed to rest his horses every other day in order to keep them in the best shape while working in Wyoming's wilderness.

America's mules have evolved into some of the most spectacular equine. They just happen to have "extra long ears."

A minimum age of 5 years is required of auction mules, and you'll see the high selling mules being shown in the mounted shooting, the team sorting and rodeo. The trail course is required so that potential buyers are able to witness the mules' qualities.

Mule Days is much more than a Father's Day auction. It is five days of family fun, vendors and an art show. A Saturday morning parade at 11 a.m. in Ralston is built around the theme of "Flags Bring Us Together," with participants urged to show their state or organizational flag.

Following a Saturday afternoon rodeo with mules in the spotlight, there is a "you-all-come" steak and hamburger dinner with all the fixin's. Then it's over to the Big Barn for a Saturday night dance to the music of Hurricane Mesa.

Cowboy Church gets the Sunday program going at 7 a.m. in the same Big Barn, which later is the setting of the Mule Days Auction at 1 p.m.

Jake Clark, a prior board member of the Rocky Mountain Elk Foundation, was inducted into the Wyoming Outdoor Hall of Fame in 2010.