Fig. 4. Nearly all of the private land in Summit County is confined to the narrow valley bottoms. The remainder of the county (about 80%) is public land (shown in gray). The Lower Blue Planning Basin occupies 722 km² (178,400 acres) in the northern part of the county. Most of the higher density zones are located in the south near the Town of Silverthorne, whereas lower density zones are located down-valley (to the north).