Sturgis motorcycle rally

Touring bikers participate in the annual Sturgis Motorcycle Rally in Custer State Park, South Dakota on August 3, 2015. Custer State Park is a popular destination for bikers during the rally and is the most heavily trafficked time at the park in the southern Black Hills.

Bikers walk along Main Street in downtown Custer while participating in the annual Sturgis Motorcycle Rally in South Dakota on August 3, 2015. REUTERS/Kristina Barker

Veronique Joking, Michelle Hansen, and Karlene Wald, all of Minnesota, take a break along the side of a highway outside of Hill City, South Dakota, during the annual Sturgis Motorcycle Rally in South Dakota on August 3, 2015. REUTERS/Kristina Barker

Bikers cruise along Main Street in downtown Custer while participating in the annual Sturgis Motorcycle Rally in South Dakota on August 3, 2015. REUTERS/Kristina Barker

Touring bikers participate in the annual Sturgis Motorcycle Rally in Custer State Park, South Dakota, August 3, 2015. REUTERS/Kristina Barker

Dog Silver, Deb Kenobbie, of Iowa, and Roger Kenobbie, of Kimball, South Dakota, watch bike traffic along Main Street in downtown Custer, South Dakota as bikers participate in the annual Sturgis Motorcycle Rally on August 3, 2015. REUTERS/Kristina Barker

Mitch McLain, dressed as General George Custer, greets bikers entering downtown Custer during the annual Sturgis Motorcycle Rally in South Dakota, August 3, 2015. REUTERS/Kristina Barker

Custer State Park assistant buffalo herd manager Doug Cox monitored motorcycle traffic from horseback during the annual Sturgis Motorcycle Rally on August 3, 2015. REUTERS/Kristina Barker

Local Charles Boyles watches the traffic along Main Street in downtown Custer with his dog Buddy during the annual Sturgis Motorcycle Rally in South Dakota on August 3, 2015. REUTERS/Kristina Barker

Tom Cuba, left, of Kearny, New Jersey, and Dan Devoe, of Queen Creek, Arizona, watch traffic along Main Street in downtown Custer while participating in the annual Sturgis Motorcycle Rally in South Dakota on August 3, 2015. REUTERS/Kristina Barker

Touring bikers take photos of buffalo calves during the annual Sturgis Motorcycle Rally in Custer State Park, South Dakota, August 3, 2015. REUTERS/Kristina Barker

Carlos Delosantos (L), Greg Delosantos, and Eliana Delosantos, cousins visiting the Black Hills from Texas and New Mexico, play at their campground outside Custer during the annual Sturgis Motorcycle Rally in South Dakota on August 3, 2015. REUTERS/Kristina Barker

Janet Nuckles (L), and husband Les Nuckles portray local historic figures Fanny and Valentine McGillycuddy as they greet bikers entering downtown Custer during the annual Sturgis Motorcycle Rally in South Dakota, August 3, 2015. REUTERS/Kristina Barker