The interstate trade of these game animals has significantly contributed to the spread of CWD throughout its current range. CWD is thought to have originally developed in northeastern Colorado at research facilities for Colorado State University. The theory that a Scrapies-infected sheep came into contact with or provided for the transmission of a mutated form of TSE to a deer has been proposed, though not conclusively. However, the disease did show up in wild deer and elk herds in the surrounding area during the 1980s, eventually spreading to Wyoming and Nebraska. It was only a matter of time before it eventually made its way into domestic deer and elk herds (McCombie, Aug. 2002). .
The growth of the game farming industry has skyrocketed in recent years. In 2001, 135,000 elk were raised on U.S. farms, increasing by 50% over the previous four years. An astonishing 500,000 deer were farmed in 2001, a figure ten-times larger than it was a decade ago. .
An interesting correlation exists between the growth of the deer and elk farming industry and the spread of CWD to areas in which it had previously not been found. Without a doubt, this industry experienced its most significant growth during the late 1990s, as the previous figures prove. Prior to this period in the 1980s and through the mid-1990s, CWD was limited to wild deer and elk populations in an area encompassing northeastern Colorado, southeastern Wyoming, and western Nebraska. However, the disease was eventually contracted by domestic elk sometime within this time frame and rapidly spread to a number of states and provinces. In fact, wildlife authorities were virtually blind to this fact until 1997 when the USDA began testing captive elk populations. As federal testing ensued, officials learned that the disease had spread throughout the Great Plains states and Midwest through the interstate trade of domestic elk and deer populations.