Claim: Northern Treasure's sire is Northfields and grandsire is Northern Dancer, the first Canadian-bred horse to win the Kentucky Derby.
Evidence: Northfields Northern Dancer Northern Dancer (May 27, 1961 – November 16, 1990) was a Thoroughbred who in 1964 became the first Canadian-bred horse to win the Kentucky Derby. 
He was sired by Northfields, an American horse whose biggest win came in the Louisiana Derby in 1971, before spending most of his stud career in Europe. Northern Dancer Northern Dancer (May 27, 1961 – November 16, 1990) was a Thoroughbred who in 1964 became the first Canadian-bred horse to win the Kentucky Derby.