A little over 170 years ago - hardly a moment on the clock of history - one half of the United States was empty of all but Indians and the plants and game on which they subsisted. Indeed, acquiring the Louisiana Territory approximately doubled the size of the United Sates, adding 800,000 square miles of land that had scarcely been explored or adequately mapped.

In The Natural History of the Long Expedition to the Rocky Mountains (1819-1820), Howard E. Evans offers a colorful history of the expedition of Major Stephen H. Long - the first scientific exploration of the Louisiana Territory to be accomplished by trained naturalists and artists. Based primarily on the expedition members' reports and diaries, and often told in the participants' own words, this fascinating chronicle transports readers back to the near-virgin wilderness of 1820.

We accompany naturalist Edwin James as he becomes the first man to climb Pike's Peak, and roam with him in his role as botanist, collecting a multitude of plant specimens, 140 of which were described by him and others as new.

We sit with artist Samuel Seymour as he sketches in vivid detail the panorama of breathtaking peaks and prominent landforms, travel along with Titian Peale as he visits the homes of Native Americans and records with an artist's keen eye and gifted hand the striking features of this land's first inhabitants, and go exploring with zoologist Thomas Say as he describes indigenous mammals, birds, amphibians, reptiles, and insects.