BLM CO Colorado River Boundary

The Colorado River polygon was created using features from the USGS Nataional Hydrography Dataset (NHD) and then digitizing the boundaries of the river from imagery...科罗拉多河多边形数据集的构建采用了美国地质调查局（United States Geological Survey, USGS）国家水文数据集（National Hydrography Dataset, NHD）中的地理要素，并通过影像对该河流的边界进行数字化处理……