Authorities say a Kelso driver fell asleep at the wheel and hit another car early Saturday on Interstate 5, near exit 30 for McMenamins and downtown Kalama.
Sarah L. Huffman, 45, was headed north at around 5:50 a.m. when she fell asleep driving a silver 2009 Mazda 3 and hit a gray 2008 Ford Focus driven by Faith M. Wright, 66, of Kalama, according to a Washington State Patrol press memo.
The Focus then hit a guardrail.
Both women were wearing seatbelts, but Wright was injured and transferred to PeaceHealth St. John Medical Center in Longview.
The exact cause of the accident is under investigation, the memo states, but troopers have found that drugs or alcohol were not involved.
