Update at 3:30 on Thursday
The crash happened 1 kilometre west of Parkbeg.
There has been a detour has been set up for eastbound traffic to proceed and it won't affect the westbound traffic.
The road will continue to be closed as the RCMP investigate the collision.
Story from 2:14 p.m. on Thursday
Drivers headed east on the Trans-Canada Highway towards Moose Jaw this afternoon will run into a closed road.
The eastbound lanes of the highway will be closed indefinitely after a serious collision by Parkbeg.
RCMP are asking drivers to plan a detour or avoid the area as they continue to investigate the crash.
Neither of the westbound lanes are being affected.