A driver was hospitalized Wednesday after a head-on collision on Interstate 25 south of Castle Rock, according to Colorado State Patrol.

Reports of a wrong-way driver at milemarker 179 near Plum Creek Road came in just after 5 a.m., State Patrol said in a news release. When troopers arrived, they found “extensive damage” to a Chevrolet pickup truck and a silver Toyota sedan. Both vehicles were blocking the road, prompting a closure of I-25 for almost an hour and a half.

The driver of the Chevrolet was transported to a nearby hospital with unknown injuries. The other driver was checked on scene by medical personnel but refused transport.

Preliminary findings show the Chevrolet was driving northbound in the southbound lanes when it hit the Toyota.

I-25 was shut down around 5:30 a.m. and reopened shortly before 7 a.m., according to Trooper Gabriel Moltrer.

He said State Patrol is still investigating what circumstances led the Chevrolet to start driving in the wrong direction.