Green River: Powell's Launchpad and the World's Trona Capital
Near Rock Springs, Wyoming
On May twenty-fourth, eighteen sixty-nine, ten men loaded four heavy wooden boats onto Union Pacific flatcars in Green River, Wyoming, and slid them into the current. The man directing the operation had only one arm, he had lost the right one at Shiloh, and no one had ever mapped what lay downstream. Major John Wesley Powell was about to find out.
Powell's expedition took ninety-nine days and covered roughly a thousand miles of river, including the first documented passage of white men through the entirety of the Grand Canyon. The launch site, a small island in the middle of the Green River just below where you are now driving, is today called Expedition Island. It was designated a National Historic Landmark in nineteen sixty-eight. Powell's boats left from this spot twice, in eighteen sixty-nine and again in eighteen seventy-one, making Green River the origin point of the most consequential river exploration in American history.
But the town has a second identity, one built not on water but on what lies beneath the desert around it. About fifteen miles west of here, underground, sits the world's largest known deposit of trona, a sodium carbonate mineral that is the raw material for soda ash, used in glass, detergents, paper, and dozens of other products. The deposit was discovered during oil and gas drilling in nineteen thirty-eight. The first mine shaft was sunk in nineteen forty-six. Today Wyoming produces the majority of the world's natural soda ash, and most of it comes from the mines ringing this valley.
The Green River Formation that holds the trona is also one of the world's most celebrated fossil beds, yielding fish, birds, plants, and insects from an Eocene lake that covered this basin fifty million years ago. Fossil hunters and geologists have been coming here since the eighteen seventies.
Powell's boats, the trona mines, the fossil beds: Green River sits at the intersection of exploration, geology, and industrial consequence in a way few small towns in the West can match.
