Lost Soldier, in northeastern Sweetwater County near the town of Bairoil, is one of the Rocky Mountains’ most complete oil fields: a sharp anticline productive from more than ten horizons, from Cretaceous Frontier sands down through the Tensleep and Madison to Cambrian rocks and fractured Precambrian basement. The Bair Oil Company drilled the discovery well in June 1916 — striking shallow oil in days — and the field, together with neighboring Wertz, has since become the heart of a long-running CO2 flood complex with cumulative recovery near 300 million barrels.
The Bair Oil Company — whose founder Charles Bair gave the town of Bairoil its name — drilled its first well at Lost Soldier on June 20, 1916, completing it just nine days later in oil found at only a few hundred feet. Development in the remote Lost Soldier–Ferris district proceeded through the 1920s as the USGS and operators mapped a string of anticlines that yielded the Lost Soldier, Wertz, Ferris, and Mahoney fields, with Lost Soldier the largest prize.
Deeper drilling revealed the field’s signature: an extraordinary stacked-pay column. Lost Soldier produces from the Cretaceous Frontier, Muddy, Lakota, and Jurassic Morrison and Sundance, the Pennsylvanian Tensleep, the Mississippian Madison, the Cambrian Flathead, and even fractured Precambrian granite — a nearly complete tour of the Rocky Mountain section on a single structure. The Tensleep and Madison proved the workhorses, and pressure maintenance and waterflooding sustained them through the mid-century decades.
The modern era began in the 1980s, when Amoco brought CO2 miscible flooding to the Tensleep at Lost Soldier and neighboring Wertz, supplied by pipeline from ExxonMobil’s LaBarge CO2 source in western Wyoming. The two fields have been run since as the integrated Bairoil complex, operated in recent years by Merit Energy, with the flood recovering oil that seventy years of primary and waterflood production had left in place. Cumulative recovery stands on the order of 290 million barrels.
Lost Soldier is a steep, faulted anticline on the Rawlins uplift margin of the Greater Green River Basin, so sharply folded that horizons from Precambrian granite to Cretaceous sandstone all trap oil on the same structure. The Pennsylvanian Tensleep — an eolian sandstone with strong CO2-flood response — and the Mississippian Madison carbonate are the principal reservoirs, with the Cambrian Flathead and numerous Cretaceous and Jurassic sands contributing. That vertical stacking is why one surface tract here can hold interests in a dozen distinct producing intervals.
The Bairoil complex hosts one of the Rockies’ longest-running CO2 projects: miscible flooding of the Tensleep at Lost Soldier and Wertz that began in the 1980s under Amoco, fed by dedicated pipeline from the LaBarge CO2 source. The flood targets a reservoir whose recovery factor under CO2 ranks among the region’s best, and successive operators have kept injection running for four decades. For mineral owners, the practical meaning is a production tail measured in decades, underwritten by continuing CO2 purchases and unit investment rather than by new drilling.
Lost Soldier interests combine century-long payment history with an unusual technical profile — stacked pays, unitized CO2 flooding, and an operator-managed injection program that governs the pace of future income. Offers based on trailing cash flow alone routinely misjudge such interests; the flood’s remaining response is where the value lives. We buy minerals and royalties in Sweetwater County directly, model the CO2 tail explicitly, and provide free written offers with our reasoning documented.
County-level well data, production charts, and selling guides for the counties this field spans:
It is the unitized operation covering the Lost Soldier and neighboring Wertz fields near the town of Bairoil, run as an integrated CO2 flood since the 1980s with CO2 delivered by pipeline from western Wyoming. Merit Energy has operated the complex in recent years.
More than ten — from Cretaceous sands like the Frontier and Muddy down through the Tensleep, Madison, and Cambrian Flathead to fractured Precambrian basement. The Tensleep and Madison have delivered most of the field’s roughly 290 million barrels.
Often yes, because flood-supported production declines slowly and reflects ongoing operator investment — value a simple multiple of recent income misses. The honest answer requires unit-level modeling, which is exactly what our free written offers include for Sweetwater County interests.