Not sure stats, at one time, only had to contain 5% angus to be sold as such.
I don't know either but I'm pretty sure that charolais bull didn't even have that much angus in it. I was in school in Golden then and that story unfolded in the paper for several months. I found the below article describing it. I had the auction amount wrong, was only $14k but that was a record price back in 1972.
One evening during the 1972 Stock Show, Jack Orr was finishing up chores down in the yards when his son and a friend came rushing into the pen. "Jeep's up there on the Hill!" they blurted breathlessly. The steer with the funny nickname had started life on the Skylark Ranch at Kremmling, Colorado, where one of the boys had prepared him for a show and sale in Kansas. He had been a creamy white Charolais back then, but now he was jet black and entered as an Angus in the Junior Show. So began a melodrama that still evokes smirks and discomfort. "No story created more publicity in National Western history," wrote former General Manager Willard Simms, but it's a story the Stock Show would sooner forget. "They took me up there and except for being black, it sure as heck looked like Jeep," Orr recalls. If it was Jeep, this was a bombshell. Only steers sired by an Angus bull were eligible to enter the Angus division and Jeep, if that's who he was, had a Charolais poppa and momma. A dye job could be the only explanation for his present hue. Soon, the barn talk was all about the steer and a protest challenging his right to compete was filed with Stock Show brass. When the owner tendered documents showing an Angus sire, the steer was allowed to stay in the competition. He conceded to using black dye to touch up a few light spots but this was a common practice and not against the rules. John Grisham might have scripted what happened next. The Angus judge, unaware of the hubbub behind the scenes, picked the animal over 86 other entries as the division champion. Two days later, a second judge chose him over Hereford and Shorthorn winners to become the Junior Show's grand champion steer, one of the highest honors at the Stock Show. "He was a good animal, no doubt about it," says Orr. The award put the critter in the headlines and when McDonald's laid down a record $14,250 at the Junior Livestock Auction and dubbed him "Big Mac," he was a celebrity.
Ordinarily, their appearance at the auction is the last curtain call for Junior Show champions, but Big Mac got a reprieve. Documents had turned up purporting to prove his Charolais ancestry and he was sequestered before he could be slaughtered. Blood samples were drawn to probe his links to the claimed Charolais and Angus sires. Branding irons from the Skylark Ranch were brought in. A vet had a gander up the champion's
nostrils for signs that pink membranes had been dyed black. "As far up as we could see, he was black," the vet said. Investigators flew to Kansas to interview the owners and 4-H officials. A brand inspector clipped hair and photographed brands from other Skylark cattle to compare with the marks on Big Mac. Separate labs turned up nary a trace of Angus blood in Big Mac's veins. He was, they said, descended from a proud Charolais lineage. The brand inspector concluded "beyond a doubt" that Skylark irons had branded him. The owner's account of the animal's provenance began to unravel and the steer started showing white around his eyes as the hair grew out. The vet peered up his nostrils again, stood back with a surprised look and proclaimed, "He's just as pink as he can be." Then the lid blew off the unfolding drama. "It hit page one of the Post noon edition," Simms would later write, "and then about every newspaper, TV and radio station in the country, and the AP and UPI wire services." To the accompaniment of media guffaws, Simms called in Big Mac's ribbons and awarded them to the reserve grand champion. McDonald's asked for a refund. Months passed and the storm subsided while Big Mac grew out a creamy white coat in pens of the Colorado Brand Board, which held him as an unclaimed stray. He had contentedly munched his way through 600 pounds of hay and 300 pounds of cracked corn by August when Iowa newspaperman Eddie Collins bought him at auction– but not to turn him into patties. "Practically everybody in the United States and a lot of Europe had heard about Big Mac," laughs Jack Orr. That fall he checked into Washington, D.C.'s, Mayflower Hotel to help stockmen dramatize low cattle prices. In a Cadillac and horse trailer Collins and Big Mac toured the country, appearing at fairs and 4-H clubs to illustrate what happens when competition goes too far. The storied steer, a champion at heart, lived to a ripe old age and might have said that things turned out just fine.