Although conservation development (CD) accounts for a growing proportion of private land conservation and residential development in the U.S., little is known about its ecological outcomes. We compiled a database of nearly 400 CD subdivisions in unincorporated areas of 19 counties in Colorado. In five counties, we also identified comparable conventional development projects, located near CD subdivisions and similar in total area and development yield. We used high-resolution aerial photography to digitize fine-scale land use and land cover within the subdivisions. We assessed the types and extent of human land use within the individual lots and protected open space of CD subdivisions, and the degree to which CD subdivisions are generating a more sustainable land use pattern than conventional development options.