Trans-Canada Highway 1 was closed 15 kilometres west of Field, B.C. due to a vehicle incident at around 3:30 p.m. Sunday.
Officials warned drivers to expect major traffic delays.
By 6 p.m., it opened to a single lane alternating traffic.
RCMP have not commented on what lead to the accident.
No word yet if anyone was injured.
One witness tweeted that a semi-trailer truck rolled between Golden and Field, B.C.