Mining at Stroh Pit

Mining Process

Sand and gravel mining often occurs along Colorado’s rivers and streams. When mining of the Stroh Pit begins, the unused sand and soil will be placed along the south and west edges of the property to create a berm to hide the operation from Thompson River Ranch residents.

The Stroh Pit mining operation will occur in two areas. A 35-acre cell on the west and a 15-acre cell on the east. Native vegetation will create a 300-foot buffer between the northern edge of the project and the Big Thompson River to avoid encroachment on the riparian corridor and preserve wildlife habitat. Additional setbacks of 266 feet to the west and 363 feet to the south also have been defined.

The Project is expected to last five to seven years, including reclamation of the mine, depending on market conditions. Mining will start in the southwest corner of the western parcel and progress north in 5-acre sections. Coulson will repeat the same pattern of extraction on the eastern parcel.

Loading trucks and crushing materials would be the noisiest part of the operation, so Coulson will reduce the noise by using a proposed conveyor belt to transport the sand and gravel produced from each cell to the Kirtright property. The proposed conveyor belt will run along the northern edge of each cell, ending at the Kirtright property, where Coulson will process the sand and gravel and load it onto trucks for transport off site.


The final step in the process is mine reclamation. After the sand and gravel mining is complete, Coulson will transform the property into an aesthetically appealing parcel of land. Coulson is considering converting the cells into lakes surrounded by open space. The west cell could be turned into a 28.4-acre lake, and the east cell into a 10.5-acre lake. The lakes would be aesthetically appealing to residents of the surrounding area, who could use the walkways surrounding the lakes as public open space. The lakes also could provide water storage or processing facilities for the surrounding communities. Coulson also is considering developing portions of the property into lakefront residential lots.

  • Coulson Aerial-Scene
  • Example

Larimer County and Johnstown Open Space Plans

The northern boundary of the property abuts the Big Thompson River, so after the property is reclaimed, it will enhance Larimer County’s 2015 Open Lands Master Plan. The plan identifies the Big Thompson River as a priority area with 1,841 acres, mostly on the Sylvan Dale Ranch, held in conservation easements.

The gravel mining operation is temporary, and while Coulson is not obligated to turn the property into open space, when the mine is reclaimed, the company plans to create lakes, walking paths and re-establish natural vegetation, which will make the property even more aesthetically pleasing than it is now.