Steven Mark Asmussen is an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 Thoroughbred

Thoroughbred

The Thoroughbred is a horse breed best known for its use in horse racing. Although the word thoroughbred is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thoroughbred breed...

 racehorse

Horse racing

Horse racing is an equestrian sport that has a long history. Archaeological records indicate that horse racing occurred in ancient Babylon, Syria, and Egypt. Both chariot and mounted horse racing were events in the ancient Greek Olympics by 648 BC...

 trainer

Horse trainer

In horse racing, a trainer prepares a horse for races, with responsibility for exercising it, getting it race-ready and determining which races it should enter...

. Born into a horse racing family, his parents, Keith and Marilyn "Sis" Asmussen, are both trainers who operate El Primero Training Center off the Mines Road in Laredo

Laredo, Texas

Laredo is the county seat of Webb County, Texas, United States, located on the north bank of the Rio Grande in South Texas, across from Nuevo Laredo, Tamaulipas, Mexico. According to the 2010 census, the city population was 236,091 making it the 3rd largest on the United States-Mexican border,...

, the seat of Webb County

Webb County, Texas

Webb County is a county located in the U.S. state of Texas. The official 2010 population for the county is 250,304. In 2000, its population was 193,117, and in 2006 its population had been estimated to have reached to 231,470. Its county seat is Laredo...

 in south Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

. His older brother, Cash Asmussen

Cash Asmussen

Cash Asmussen is an American thoroughbred horse racing jockey. Born Brian Keith Asmussen, in 1977 he legally changed his name to "Cash". From a Texas horse racing family, his parents, Keith and Marilyn "Sis" Asmussen, operate a ranch in Laredo, Texas...

, currently a trainer himself, is a retired Eclipse Award

Eclipse Award

The Eclipse Award is an American thoroughbred horse racing award named after the 18th century British racehorse and sire, Eclipse. The Eclipse Awards, honoring the champions of the sport, are sponsored by the National Thoroughbred Racing Association , Daily Racing Form and the National Turf Writers...

-winning jockey and a champion in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

.

Asmussen began racing at age sixteen as a jockey, competing at racetracks in New Mexico

New Mexico

New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

, and New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 for three years until his height and weight ended his riding career.