Historic Oil Field
Steamboat Butte Field lies northwest of Riverton in Fremont County, Wyoming, in the Wind River Basin, and it was one of the significant wartime discoveries in the Rocky Mountains. The discovery well was completed in March 1943, and by the middle of 1947 only sixteen producing wells had been drilled — yet the field had already yielded more than four and a half million barrels and ranked among Wyoming’s largest by proved reserves. Oil comes from the Jurassic Nugget sandstone and the Pennsylvanian Tensleep, with gas in several Paleozoic units.
The discovery well was completed in March 1943, at a moment when Rocky Mountain exploration was under wartime pressure to find domestic crude quickly. Steamboat Butte answered that pressure: within four years, sixteen producing wells had delivered over four and a half million barrels, an average per-well performance far above what most Wyoming fields of the era could show. Detailed field descriptions were published in the 1948 Wyoming Geological Association field conference, which is the sort of attention reserved for discoveries the industry considered genuinely important.
The field’s productive column reflects the Wind River Basin’s stacked character. Oil was found in the Jurassic Nugget sandstone and in the Pennsylvanian Tensleep, while gas occurs in the Tensleep together with the Phosphoria, Amsden, Embar, and Sundance formations. Development therefore involved managing several distinct reservoirs on one structure, each with its own pressure regime and gas-oil relationships. That complexity is typical of the Steamboat Butte and Pilot Butte area, which the USGS mapped in detail because of the number of horizons involved.
The decades since have followed the familiar Wyoming pattern of unitization, injection to maintain pressure, and long slow decline into stripper-rate production. Operatorship of Wind River Basin properties has consolidated repeatedly, and the older units have generally moved toward smaller companies that specialize in mature waterfloods. Owners should also be aware that Fremont County contains extensive Wind River Reservation acreage, and that the legal footing of a mineral interest in this county depends entirely on whether the tract is fee land or reservation trust land.
Steamboat Butte is a structural trap in the northwestern Wind River Basin, part of the Steamboat Butte and Pilot Butte area the USGS mapped for its multiple productive horizons. Oil is produced from the Jurassic Nugget sandstone, a clean eolian unit, and from the Pennsylvanian Tensleep. Gas is present in the Tensleep and in the Phosphoria, Amsden, Embar, and Sundance formations. That stacking means a single tract can carry interests in several separately managed reservoirs, and it explains why early per-well performance here was strong relative to fields with one thin pay.
Like nearly every long-lived Wyoming structural field, Steamboat Butte has depended on pressure maintenance and water injection to extend recovery well past what primary depletion would have allowed. In stacked reservoirs the practical difficulty is that each interval responds differently, so injection has to be balanced zone by zone rather than treated as a single flood. The consequence for owners is a production profile that is low but persistent, with the pace of decline set by an operator’s injection and workover program rather than by the geology alone.
Steamboat Butte interests are typical mature Wind River Basin royalties: modest, slow-declining, and often divided among heirs who have never seen the unit agreements involved. The first question with any Fremont County interest is jurisdictional — whether the tract is fee minerals or lies within the Wind River Reservation, where trust and allotted interests are administered by the Bureau of Indian Affairs and are not conventional fee minerals we can purchase. Where the interest is fee, we buy minerals and royalties in Fremont County and provide free written offers.
County-level well data, production charts, and selling guides for the counties this field spans:
Unusually so for the era. Sixteen producing wells had been drilled by the middle of 1947, and they had already produced more than four and a half million barrels, which placed the field among Wyoming’s largest by proved reserves only a few years after its March 1943 discovery.
Oil comes from the Jurassic Nugget sandstone and the Pennsylvanian Tensleep. Gas is found in the Tensleep along with the Phosphoria, Amsden, Embar, and Sundance formations, so a single structure carries several separately managed reservoirs.
The legal description and the chain of title answer it. Tracts inside the Wind River Reservation boundary are generally trust or allotted interests administered federally rather than fee minerals. If you send us a legal description we will tell you which you hold before anything else is discussed.