Snowy conditions led to a one car rollover crash yesterday morning in Port Huron Township.  According to St. Clair County Sheriff Tim Donnellon, 48 year old Alison Brown of Port Huron was travelling westbound on Dove Road near Michigan Road, when she lost control of her vehicle just before 9:30.  The Mercury Sable left the road, went into the ditch and struck a culvert.  The Vehicle then rolled on its side.  Port Huron Township and Kimball Township Fire and Rescue were called to assist and had to remove Brown from the vehicle with the Jaws of Life. Tri-Hospital EMS also assisted at the scene.  Brown suffered minor injuries, but was not taken to the hospital.  Thursday saw a total of seven property damage crashes, two injury crashes and four vehicles in the ditch reported countywide from 8:30 a.m. – 4:00 p.m.  With more snow expected, Sheriff Donnellon is again urging drivers to give themselves plenty of extra time to arrive at their destination to avoid a crash on slippery roads.