First time visitors to Golden Gate Park are often surprised to see buffalo grazing in a small valley alongside John Kennedy Drive. Bison (the correct name for the species more commonly called buffalo) were first introduced into the park in 1899. In 1851 there were more buffalo in the United States than there were people. Various estimates of the number of buffalo in 1851 vary from 75 million to over 100 million. A surveyor for Thomas Jefferson, caught in the middle of a massive herd that stretched to the horizon in all directions, traveled along with it atop a high ridgeline for two weeks, and using his instruments, estimated the herd that he was surrounded by, to be the size of the state of Pennsylvania. Wagon trains sometimes had to stop for weeks to allow the grazing migrating ocean of brown shaggy beasts to pass by. Steam trains were often knocked off the tracks by a stampeding herd, and miles of telegraph poles knocked over and pushed down by the massive animals rubbing and scratching their backs on the treeless prairie. With the settling of the west by white homesteaders, and the final conquest of the remaining warring Plains Indians, in a period of less than fifty years, fueled by a deliberate Federal government and military sponsored campaign to eradicate the animal from the Great Plains, this unique creature was nearly brought to complete extinction. In 1899, when San Franciscans had their first sight of this majestic animal in Golden Gate Park, there were only 400 buffalo left in all of North America.