Laguna Madre is a long backwater bay that extends 130 miles south from Corpus Christi Bay to Port Isabel between Padre Island and the mainland. It fronts southern Nueces County, all of Kleberg, Kenedy, and Willacy counties, and most of Cameron County. It is four to six miles wide and very shallow, in many places only eight to fourteen inches deep, except for the dredged areas of the Gulf Intracoastal Waterway. It was always fordable in some places until the construction of the canal. Pat Dunn is reported to have forded his cattle through it to and from Padre Island. The Gulf Intracoastal Waterway traverses the entire length of the Laguna Madre with a shipping channel 125 feet wide and twelve feet deep. The canal provides the Port of Brownsville with a protected channel to all the other Texas ports.