White Pine Hollow is a 712-acre preserve featuring a rugged landscape with groves of white pine trees. Formerly known as “Pine Creek Hollow” and “Pine Hollow,” it is two miles northwest of Luxemburg in northwest Dubuque County. Interest began in the early 1920s for Pine Creek Hollow to become an “unimproved” state park. In 1932, the Dubuque High School Nature Club began construction of a cabin to serve as a nature school headquarters, and it was dedicated to Ross Harris, founder of the Pine Hollow movement. The Dubuque County Conservation Society contributed funds toward the purchase of the area, leading to the acquisition of the first 80 acres in 1934 by the Iowa Conservation Commission as a state forest. The area was dedicated as a biological and geological state preserve in 1968 and as a National Natural Landmark in 1972. Located along the western edge of the Paleozoic Plateau landform region, the deeply dissected, bedrock-dominated topography of this preserve lies on the prominent Silurian Escarpment. This line of steep rock bluffs marks the eroded edge of hard, resistant Silurian-age dolomite. Terrain is typical of the Silurian Escarpment, with numerous large rock outcrops, slump blocks, cliffs, sinkholes, caves, algific talus slopes, springs, and steep-walled valleys. The deep valley of Pine Hollow Creek and three extensive branches cut through the preserve. The “hogsback,” a nearly isolated narrow upland ridge formed by the meandering creek, can be found in the southeastern portion of the preserve. A “rock city” of separated massive slump blocks occurs just north of the hogsback. Precipitous bluffs occur throughout the preserve. The preserve’s highest point, at 1,140 feet, is about 320 feet above its lowest elevation