Lance Rosier was an early advocate for conservation and wildlife preservation whose efforts helped make the Big Thicket National Preserve possible. Born in what is now the Preserve unit that bears his name, he grew up in Saratoga in the center of the Big Thicket, living with his aunt Mattie Evans in her Vines Hotel, where he listened to stories told by roughnecks, drummers and pioneers. He spent much of his youth wandering the nearby woods and learning about native flora and fauna. After serving in the U.S. Army, he became a timber cruiser and a guide for surveyors. Authors and journalists wrote numerous stories about the self-taught naturalist, who provided tours for scientists, photographers, politicians, students, scholars, conservationists and others seeking his expertise. His knowledge grew through work with scientists who identified plants for him and expanded his understanding of habitats, life cycles, medical or industrial uses, and scientific names of plant species. His tours also featured stories such as an encounter with a black panther. Known as "Mr. Big Thicket," Rosier served as a bridge between the first East Texas Big Thicket Association, founded in 1929 and led by R.E. Jackson, and the effort to establish the second Big Thicket Association in 1964. He died in 1970, a few years before his hope of having the unique environmental area declared a national park was realized, and his legacy endures in the protection and continuing research of the Big Thicket.