An Adams man has been charged with driving a van while using a controlled substance with a minor child in the vehicle.  According to the criminal complaint, 29-year old Ryan Sharp was operating a mini-van last month that was involved in a drug investigation.  Adams County authorities had obtained a GPS warrant and installed the device on the vehicle.  An investigator conducted surveillance as the van left a factory in the Mauston Industrial Park and traveled to Madison.   28-year old James Sieger of Friendship and his minor son were passengers.  On the trip back to Adams, Sharp stopped at a fast food restaurant and allegedly both Siegert and Sharp injected the drug.  During the investigation, Siegert had admitted to buying heroin.  He has been charged with 2-counts of possession of narcotics and three counts of child neglect.  Sharp has been charged with being a party to possession of narcotic drugs and operating with a restricted controlled substance in the blood, 1st offense, with a minor in vehicle, among other charges.