The McDowell County Sheriff's Department says Thomas Keith Henderson of Elkhorn was arrested late Wednesday during a traffic stop on Burke Mountain near Keystone.
A criminal complaint says Deputy R.L. Jones stopped the snow plow because the driver's side headlight was out. The deputy smelled alcohol and saw that Jones' eyes were bloodshot and glassy.
The sheriff's department says Henderson's blood alcohol level was 0.09. That's more than twice the 0.04 legal limit for commercial driver's license holders.
DOT spokeswoman Carrie Bly confirmed Henderson is employed by the department. She says the DOT can't comment because it's an ongoing legal matter.
A telephone listing for Henderson in the Elkhorn area couldn't be found.