The darker side of any larger motorcycle event is adding its footnotes to the 70^th anniversary of Sturgis with more riders becoming highway fatalities.

Thursday saw the number rise to eight bikers that have died since the start of the Sturgis Motorcycle Rally with Daniel Maddaus, of Las Vegas and Dennis Knouse, of Huron becoming the latest names added to an unfortunate list. Ironically, both were 52 years old.

Maddaus reportedly lost control of his motorcycle on U.S. Highway 83 south of Murdo when his 1997 Harley-Davidson motorcycle began to fishtail. He lost control and went into the ditch and was fatally injured in the crash. He was not wearing a helmet.

According to the highway patrol Knouse was killed when his 2002 Harley-Davidson motorcycle crossed the center line of Silver City Road in Rapid City and collided with an oncoming motorcyclist on a 2010 Harley-Davidson. The other rider, Thomas Barb, 52, of Garden City, received minor injuries.

Neither Knouse nor Barb were wearing helmets and although no citations were issued, alcohol is believed to be a factor in the crash.

While the two latest fatalities bring the official number of deaths related the annual Sturgis Motorcycle Rally to eight at least 10 other deaths in South Dakota and Iowa are believed related to the rally.

On a lighter note, motorcycle enthusiasts appear to have an affection for presidential history and national landmarks. Park Rangers are reporting record breaking numbers as 17,600 people visited the nearby Mount Rushmore Tuesday. With most of those reportedly being bikers in the areas for the rally, officials say the attendance was the most in one day since the park started keeping track in 2000.