State troopers have made three marijuana busts in the past few weeks. The biggest was yesterday in southwest Iowa with a haul worth more than a half-million dollars. Highway Patrol spokesman Sergeant Rob Hansen says a trooper in Cass County happened across a motor home on Interstate 80.The motor home was weaving and going slow compared to other traffic. The trooper pulled the motor home over near the Anita exit and after a brief talk, the driver hopped out and ran into a field. He was apprehended after a short foot chase. Hansen says 380 pounds of marijuana was found in the camper worth 570-thousand dollars.38-year-old George Grant of Baltimore, Maryland, was arrested on a variety of charges. An unnamed female juvenile was also taken into custody. Charges against her are pending. Sergeant Hansen says this is one of the largest pot busts this year by the patrol, and the third in ten days.The other busts were 120 pounds in Dallas County and 150 pounds in Pottawattamie County. There was another marijuana seizure early this year that netted 990 pounds.