Wesley Clark was born near Hanford in Kings County, California, in 1882. He spent his life in agriculture, principally as a breeder of Holstein-Friesian cattle. In 1915, the year he bought his first animal, he became a member of the Holstein-Friesian Association. His parents had been breeders of registered cattle for some years before this. Until 1948, he worked with his mother and his brother, Wallace, developing the Clark herd. Later he managed his own herd.
One of his cows was the first in Kings County to be classified "excellent". He owned the first bull to receive the Gold Medal rating and the second bull classified as "excellent". He bred one of the highest producing cows of the breed, Naomi Bessie, which had a lifetime record of 249,552 pounds of milk and 8,455 pounds of fat.
Mr. Clark was one of a few breeders to receive the Holstein-Friesian Progressive Breeders Award. He was active in National Holstein work, was a state director of the California Holstein-Friesian Association, and president of numerous Kings County farm organizations.
Next to dairy cattle, his greatest enjoyment was making labor-saving devices and farm machines from scraps and junk. These inventions, which were never patented, were often featured in national farm magazines. He designed the first satisfactory slope-sided barn for chopped hay, and the first above-ground plank pit silo. He enjoyed giving his ideas away for others to use.