Third Cadence, a developer known for large-scale residential projects across the West, has begun work on Settler Springs Village, a planned community within the broader Mayfield Townsite development in Elmore County, Idaho, southeast of Micron’s expanding Boise campus. The initial phase covers 1,400 acres and is designed to accommodate approximately 1,400 homes, with the entire Mayfield Townsite potentially supporting up to 15,000 residences across its 5,000-acre footprint.
Third Cadence’s track record includes Daybreak in South Jordan, Utah, which spans 4,100 acres and has built more than 9,300 homes with another 10,000 planned, as well as Terraine in West Jordan, Utah, a 634-acre community featuring 2,817 homes. The company’s entry into the Elmore County market represents a significant expansion of residential development in the region, an area that has drawn increasing interest from builders and investors as Micron Technology’s semiconductor expansion reshapes the broader Ada County and Treasure Valley landscape.
Mayfield Townsite Background and Entitlements
The Mayfield Townsite project originated in 2021 when property owners Teresa and John McCallum sought preliminary plat approval from Elmore County. In subsequent years, Mayfield Ranch Estates LLC purchased 1,400 acres from the McCallums, with options to acquire additional land. County planners approved a preliminary plat for Settler Springs Village within that parcel, granting entitlements for up to 3,000 homes. The 2023 preliminary plat divides the wider development area into 14 distinct planning zones, each designed to coordinate infrastructure, open space, and recreational pathways.
The master plan incorporates equestrian and ATV access routes, water storage facilities, open green space, and networks for pedestrian and bicycle traffic—design elements reflective of Elmore County’s rural character and the lifestyle preferences of potential residents in the region.
Infrastructure and Construction Timeline
Third Cadence officials indicate the project remains in its early planning stages. David Crowder, a representative for the developer, stated that infrastructure coordination and engineering analysis will require approximately one year before construction can commence. “We’re looking at that as phase one, so future phases would come along later, assuming that we’re successful in everything,” Crowder said, indicating that the 1,400-home initial phase represents only the first step in a much larger build-out.
Crowder added that “timing will ultimately depend on further analysis and coordination with public agencies,” underscoring the complexity of permitting and infrastructure alignment required for a project of this scale in a largely rural county.
Unlike developments served by municipal water and sewer systems, Mayfield Townsite will operate its own wastewater treatment facility and water system. This requirement means Third Cadence must design and construct independent infrastructure rather than rely on existing utility providers—a factor that extends the pre-construction timeline and adds significant capital investment before the first shovel hits the ground.
Development Context in Elmore County
The Settler Springs Village project arrives amid broader transformation in the broader Boise area. Micron’s multibillion-dollar semiconductor fabrication plant expansion has catalyzed interest in residential development throughout southeastern Ada County and adjacent Elmore County. The Mayfield Townsite is one of several large-scale projects underway or planned in the region, alongside Mayfield Springs—which is currently under construction—as well as Peregrine, a mixed-use commercial and industrial complex. Additionally, the Coeur d’Alene and Shoshone tribes have proposed a gaming facility in the area, which would introduce a different economic driver to the region.
As these projects advance, infrastructure demands—water supply, roads, power, and wastewater capacity—will place increasing pressure on county resources and coordination with Ada County Highway District (ACHD) and other regional agencies. The phased approach Third Cadence is pursuing allows the developer to refine its infrastructure plans while monitoring market conditions and public-agency readiness to support large-scale residential growth.
What Comes Next
Prospective buyers and local officials should expect continued engineering and environmental studies over the coming year. Third Cadence will coordinate with Elmore County planners, the Ada County Highway District, and state agencies to finalize road alignments, utility capacity, and development conditions. Once that coordination concludes, early construction activity—likely focused on infrastructure and model homes—could begin in 2027 or later, contingent on market demand and permitting timelines.
Residents interested in the project’s progress or wishing to attend county planning meetings can contact the Elmore County Planning and Zoning Department for updates on future public hearings. The broader Mayfield Townsite development will reshape Elmore County’s character and tax base significantly over the coming decade, making continued public engagement essential for both county officials and neighboring property owners.