REDDING, Calif. -

A Shasta Lake man could face prison time after pleading guilty to a drunk driving accident that killed his 17-year-old cousin.

Cody Munson, 23,  pleaded guilty Thursday in Shasta County Court to gross vehicular manslaughter while intoxicated.

The deadly accident happened July 11, 2013 in Burney.

According to prosecutors, Munson had been drinking alcohol with the victim and her boyfriend earlier in the day.  One witness said Munson "seemed to be showing off," while driving the ATV on a dirt road near Goose Valley Road.

Munson told investigators he was driving 35-40 miles per hour and hit a rock which caused the collision.  The victim was riding on the back of the ATV, was ejected and hit a tree.

After the collision, Munson placed the victim on the ATV and drove to the Pit River Mini Mart seeking help.  She was taken to Mayers Memorial Hospital and then taken by helicopter to Mercy Medical Center in Redding where she was pronounced dead.

CHP officers said Munson had a blood alcohol level of .10% and he was arrested for gross vehicular manslaughter while intoxicated.

Munson will be sentenced July 17 and could face prison or probation.