Lost Maples State Natural Area preserves 2,906 acres of hills, canyons, river habitat, and distinctive plant life along the upper Sabinal River in the Texas Hill Country. Acquired by Texas in 1973 and 1974, opened to the public in 1979, and recognized as a National Natural Landmark a year later, it is managed primarily to protect landscape and habitat rather than maximize recreation. The area is especially significant for its stands of bigtooth maples, considered relics of a broader population from the last glacial period, and for its rich wildlife, abundant birdlife, and reliable river water that helps sustain aquatic life even during severe drought.