Lambton County is a county in Southwestern Ontario, Canada. It is bordered on the north by Lake Huron, which is drained by the St. Clair River, the county’s western border and part of the Canada-United States border. To the south is Lake Saint Clair and Chatham-Kent, another county in Ontario. Lambton County’s eastern border follows the Ausable River north until it reaches Lake Huron at the beach community of Grand Bend. The county seat is in the Town of Plympton-Wyoming.
Lambton County started as a part of the District of Hesse. The district of Hesse included British territories west of Long Point, (practically all of western Ontario). The district was latter divided and renamed using English district names (Essex, Suffolk, Kent, etc.). Lambton was part of Kent county. In 1849 districts were abolished and the County of Lambton was formed. Lambton and Kent first shared the capital city of Sandwich (since renamed as Windsor, Ontario). In 1852 the partnership was dissolved and Lambton become a full county. It is named in honour of the Earl of Durham who lived in Lambton Castle.
The largest city in Lambton County is Sarnia, which is located at the mouth of the St. Clair River. The two Blue Water Bridges cross the river at Sarnia, connecting it to Port Huron, Michigan. The bridges are one of the busiest border crossings between the two countries. The river is also traversed by two passenger ferries further south, and a rail tunnel, also at Sarnia, runs underneath it. The CN rail tunnel accommodates double stacked rail cars.