The Boulder County commissioners recently agreed to a staff request to delay closing on the planned purchase of Cemex’s Dowe Flats property until the initial reclamation of the land is complete and the state has signed off.

The 766-acre Dowe Flats property, which includes the plant’s closed quarry and a conveyor, is north of Colo. 66 and adjacent to Rabbit Mountain open space. The cement plant, which is still operating, is a separate property located on the other side of Colo. 66.

Boulder County plans to purchase the 766 acres, which are split into two separate Dowe Flats parcels, through its open space fund, with a goal of returning the site to a native grassland.

The smaller, 153 acre-parcel includes the rights to develop 11 lots. In exchange for the county purchasing the $5.1 million in development rights, Cemex will transfer the 153 acres to the county for open space. The county commissioners signed off on the purchase in October, and the original deadline for the county to buy the development rights under a 2002 agreement was the end of December.

The county also has the option to purchase the larger, 613-acre property as part of that 2002 agreement. The county had planned to pursue that option when it became available early this year, according to a staff memo.

Under the new agreement, the county will wait to purchase the development rights for the smaller property and to purchase the larger property until the primary reclamation efforts have been completed. Only long-term activities, such as monitoring the effectiveness of planting and reseeding, should remain, according to the county.

“Staff will continue working with CEMEX throughout 2025 to conduct the county’s due diligence and accomplish the closing as soon as possible,” according to a staff memo. “If all goes smoothly, closing could occur in late 2025.”

In a written statement, Cemex officials said the company and the county mutually agreed to extend the closing.

“This simplifies the necessary paperwork and avoids potential confusion over access as reclamation continues,” Cemex officials wrote.

The Dowe Flats quarry closure came after Boulder County commissioners in 2022 denied Cemex’s application to continue mining at the quarry for 15 more years. The county had authorized Cemex in 1994 to mine the quarry for a maximum 25-year period.

As the county moves forward with acquiring the Dowe Flats land, it’s also trying to shut down the cement plant.

Boulder County in April sent a letter to Cemex terminating the company’s right to operate the plant. The letter cited a Colorado Department of Transportation traffic study that, county officials said, showed increased traffic created a hazard and expanded the use of the plant.

The plant has operated outside Lyons since 1965, according to the county.

Cemex has appealed Boulder County Community Planning and Permitting Director Dale Case’s determination that the plant must close. In a Nov. 7 written response to the termination notice, Cemex officials countered that a few Boulder County residents are using the traffic study as a pretext to accomplish their mission of getting the plant closed.

Case said county staff members are reviewing Cemex’s appeal, as well as materials submitted by the Friends of Lyons group that’s advocating for the closure.

A global building materials company, Cemex operates 10 cement plants and about 50 cement terminals across its U.S. network.