MONDAY, July 27, 2026|
Photo – Subsidence off of CR 291 – by Matt Copeland Bigfoot99
County officials approved the Abandoned Mine Land Division’s latest project.
During the July 20th Board of Carbon County Commissioners meeting, Road and Bridge Superintendent Kandis Fritz announced that the Wyoming Department of Environmental Quality’s Abandoned Mine Land Division is preparing to work on County Road 291, also known as Hanna Draw Road. Fritz presented a contract between the county and the state agency for Commission Chairman Travis Moore’s signature.
Chairman Moore asked Fritz to explain why the Abandoned Mine Land Division intends to drill into County Road 291 and why attorneys are involved with the project. The Road and Bridge superintendent explained that the state will use a special slurry mixture to fill underground mines and prevent them from collapsing.
Deputy Attorney Ashley Davis added that the contract is needed to cover any accidental damage to county property.
The Town of Hanna, originally named Chimney Springs, was founded in 1889 to supply coal for the Union Pacific Railroad. According to the Environmental Protection Agency, the Hanna coalfield covers roughly 750 square miles. Over the town’s 137‑year history, countless mine workings were dug, reaching depths between 30 and 330 feet beneath the surface. After the mining companies left in the early 2000s, the ground settled, water entered the mines, and roof supports failed, creating large surface voids known as subsidence.
The voids have been a persistent problem for the town. Active subsidence regularly opened near the original Hanna Elementary School, on the corner of School and 2nd streets. A new school was built two blocks to the north and the state’s Abandoned Mine Land Division began a nearly $10 million subsidence mitigation project to fill the Hanna Number Four mine with 42,500 cubic yards of void-filling grout.
Just two years after that project was completed, a subsidence opened on County Road 297, one of two major routes connecting Hanna to Highway 30. Contractors with the Abandoned Mine Land Division drilled into the mines and pumped a special slurry mixture into the underground voids, making the road safe to drive on. However, one year later in July 2024, County Road 297 was closed again after another cavity was discovered but Abandoned Mine Land Director Don Newton reported that it was most likely caused by a collapsed drill hole and not a new subsidence.
And now, more voids have started opening north of Hanna, on County Road 291.
The Board of Commissioners unanimously voted to have Chairman Moore sign the Surface Owner Consent agreement with the Abandoned Mine Land Division and the state’s contractor, BRS Engineering Incorporated.
