From the Times Call:
Boulder County has closed Lefthand Canyon and James Canyon to cyclists until May 1 while crews remove major debris hazards and continue road construction there.
County officials also encouraged motorists to avoid the canyons' roads unless travel is necessary. The closings to cyclists began on Friday and are to be in effect seven days a week.
County Transportation director George Gerstle said in a news release that the closings of Lefthand and James canyons' roads are “due to unsafe conditions on the roadways such as steep drop-offs along the roadways from washed-away ditches and washed-away roadside shoulders, plus the increased volumes of heavy construction and road maintenance equipment along compromised roadways.”