GRSM_12K_TOPO_BOUNDARIES

This layer presents the geographic extent of USGS 1:12,000 topographic maps for the conterminous U.S. forty-eight states and District of Columbia. It provides quadrangle name, identification number, publication data, and map coverage by state for each quadrangle. This large-scale index grid can be a handy visual reference for regional displays. These data are a subset of a larger dataset published by the organization listed in the credits. Great Smoky Mountains National Park makes these data available in this form such that users can: effectively manipulate data for park mapping activities that do not require the acquisition of a large, nation-wide data set; alter symbology and rendering parameters natively; restrict analysis of geospatial data to an extent that coincides with the park footprint. The corresponding Integration of Resource Management Applications (IRMA) NPS Data Store reference is Great Smoky Mountains National Park 1:12,000-scale Topographic Map Boundaries.本图层呈现了美国地质调查局（USGS）面向美国本土四十八州及哥伦比亚特区发布的1:12000比例尺地形图的地理覆盖范围。该图层可为每个矩形图幅（quadrangle）提供图幅名称、标识编号、出版信息以及各图幅的州域覆盖情况。该大比例尺索引网格可作为区域可视化展示的便捷参考依据。此类数据为致谢名单中所列机构发布的更大规模数据集的子集。大烟山国家公园（Great Smoky Mountains National Park）以该形式提供此类数据，使使用者可开展以下操作：针对无需获取全国性大型数据集的公园制图工作，高效处理相关数据；原生修改符号体系与渲染参数；将地理空间数据分析的范围限定为与公园地理覆盖范围（footprint）相一致的区域。对应的资源管理应用集成（IRMA）美国国家公园管理局（NPS）数据存储参考条目为：大烟山国家公园1:12000比例尺地形图边界。