The Thoroughbred/Chincoteague cross has been popular for producing sport ponies. Most are considered partbreds but there's been some instances where they have become part of the Chincoteague bloodline.
A source quoted in The Wild Horse Dilemma by Bonnie Gruenberg stated a Thoroughbred stallion named "Red" lead a band of mares on Assateague in the 1960's. This would be within the same era of the well documented Arabian outcrossing.
Beaufort Farms of Harrisburg, Pennsylvania bred at least one Thoroughbred cross. The 1956 born colt Leap Year was sired by a Chincoteague stallion and out of a 7/8 Thoroughbred mare. He was described as a crossbred pony in Ponies for Young People by Ehrman Mitchell. It's unknown if Leap Year sired any foals and if they were considered Chincoteagues or partbreds.
A source quoted in The Wild Horse Dilemma by Bonnie Gruenberg stated a Thoroughbred stallion named "Red" lead a band of mares on Assateague in the 1960's. This would be within the same era of the well documented Arabian outcrossing.
Beaufort Farms of Harrisburg, Pennsylvania bred at least one Thoroughbred cross. The 1956 born colt Leap Year was sired by a Chincoteague stallion and out of a 7/8 Thoroughbred mare. He was described as a crossbred pony in Ponies for Young People by Ehrman Mitchell. It's unknown if Leap Year sired any foals and if they were considered Chincoteagues or partbreds.
Misty's Twilight was the subject of a Marguerite Henry book and was sired by the Thoroughbred Big Bluffer. However she is generally considered to be a partbred.
Stormy's oldest daughter Windy, born in 1969, was sired by a Thoroughbred. She was the result of an accidental breeding of Stormy with a racehorse trained by Ralph Beebe. His name is unknown at this time. Windy is "officially" listed in the Pictorial Life Story of Misty as being by a Chincoteague stallion named Lightning.