Patrick Dunn was born in Corpus Christi in 1858 and began working with cattle on the open range as a teenager. Dunn decided, along with his brother, to establish a ranch on Padre Island. Dunn leased a portion of the island's north end in 1879 and brought out 400 cattle. In 1907 Dunn built a two-story house on Packery Channel using drift lumber found on the beaches.
Dunn became known as the "Duke of Padre" and his Mexican ranch hands called him Don Patricio. When the first causeway to the Island opened in 1927, it was named the Don Patricio Causeway.
Reportedly, after the Nicaragua wrecked on the southern end of the ranch in 1913, Dunn used furniture from the ship to furnish his house. In 1916 a hurricane demolished the house.
Dunn enjoyed the solitude of the Island and he became especially resentful of its growing popularity and maintained posted signs along the Island. One writer described Dunn's antipathy for fishermen as "Fishermen meant sports, sports meant tourists, and tourists meant civilization coming too close to Padre."
Pat Dunn sold his Padre Island interests in 1926, retaining grazing rights, which he used until his death March 25, 1937. His son, Burton Dunn, continued ranching operations until his death Sept. 8, 1970, after which the last cattle were removed from Padre Island.