Lake County officials say Wesley Jean Couture, of Billings, Mont., was on parole from a 2003 DUI when a Flathead tribal officer observed his vehicle cross the center line in Pablo on Sept. 6, 2009. Court records say Couture failed several field sobriety tests and refused a breath test.
A jury deliberated about two hours Tuesday before convicting him.
A prosecutor says Couture was found guilty of his ninth DUI in March 2003 and was sentenced to 10 years with the Department of Corrections, with seven suspended.
Couture is scheduled to be sentenced July 14. Because of a previous parole violation, it's unclear how many years in prison he faces.