Balancing housing growth and land conservation: Conservation development preserves private lands near protected areas

•We document 343 conservation developments (CDs) in 13 Colorado counties, protecting 19,744 ha of open space.•CDs occupied <1% of land area, but comprised 11% of private protected land.•The majority (76%) of CDs are adjacent to protected areas.•Targeted placement of CDs and coordinated management across CDs and protected areas will increase their conservation benefits.