Christopher Millspaugh, 22, was heading west on a 2007 Suzuki motorcycle around 1:30 a.m. Monday when the motorcycle went off the right shoulder, hitting the concrete barrier and a light pole, Idaho State Police report.
Millspaugh, who was wearing a helmet, was thrown from the motorcycle and landed off the roadway, near Front Street, according to an ISP news release.
He was taken by ambulance to Saint Alphonsus Regional Medical Center in Boise. The crash happened on Interstate 184, the Connector, near 17th Street. He was listed in critical condition at 7 a.m. Monday.