Two elderly drivers were hospitalized Friday at Sacred Heart Medical Center in Spokane, Wash., following a head-on crash south of Bonners Ferry, Idaho.

Narven E. Osteen, 77, of Libby was southbound on U.S. Highway 95 near milepost 504 when, for an unknown reason, he drove his 2007 Ford sedan left of the center line and struck head-on a 2005 Toyota Corolla driven by Elizabeth L. May, 80, of Bonners Ferry.

The crash, which was reported at 11:59 a.m. Friday, blocked both lanes of the highway for about two hours, according to an Idaho State Police report.

Both drivers were transported by air ambulance to Sacred Heart, where Osteen was listed in critical condition and May was listed in serious condition on Friday evening.

Both drivers were wearing seat belts at the time of the crash.

An investigation was ongoing.