U.S. Fish and Wildlife Service National Realty Tracts

This data view depicts lands and waters administered by the U.S. Fish and Wildlife Service (USFWS) in North America, U.S. Trust Territories and Possessions. It may also include inholdings that are not administered by USFWS. The primary source for this information is the USFWS Realty program. These are resource grade mapping representations of the U.S. Fish and Wildlife Service boundaries. For legal descriptions of the land represented here, contact the USFWS Realty Office. This map layer was compiled by the U.S. Fish and Wildlife Service. Although these boundaries represent lands administered by the U.S. Fish and Wildlife Service, not all areas are open to the public. Some fragile habitats need to be protected from human traffic and some management areas are closed. The public is urged to contact specific Refuges or other conservation areas before visiting. Data can also be downloaded from ServCat, the FWS Catalog. Go to this link for downloadable cadastral data: https://iris.fws.gov/APPS/ServCat/SavedSearch/Profile/2674 This dataset contains features which have been modified from the source regional data. For select features, geometry has been generalized up to a specified threshold to reduce a high number of vertices in large multipart polygons and improve web service performance. Currently five or fewer features are generalized in each dataset, with the generalization tolerance varying from 1m up to 30m per feature, as required. To further improve web service performance: OGC geometry problems were automatically fixed where possible, true curves were densified, and the data were projected into the WGS 1984 Web Mercator Auxiliary Sphere projection. Sync is enabled, but editing is disabled. POC for these data are: [e-mail]本数据视图展示了由美国鱼类及野生动物管理局（U.S. Fish and Wildlife Service, USFWS）在北美、美国托管领土及属地范围内管理的土地与水域。 其亦可包含并非由该局管理的内部地块。 本数据集的核心信息来源为美国鱼类及野生动物管理局不动产项目（USFWS Realty program）。 本数据为美国鱼类及野生动物管理局辖区边界的资源级测绘成果。 如需获取此处所展示土地的法律说明，请联系美国鱼类及野生动物管理局不动产办公室。 该地图图层由美国鱼类及野生动物管理局编制。 尽管上述边界代表该局管理的土地，但并非所有区域均对公众开放。 部分脆弱栖息地需免受人类活动干扰，部分管理区域亦处于封闭状态。 故敦促公众在前往参观前，先联系具体的野生动物保护区或其他保护区域。 数据亦可从FWS目录系统ServCat下载获取。 可访问以下链接获取可下载的地籍数据：https://iris.fws.gov/APPS/ServCat/SavedSearch/Profile/2674 本数据集包含源自原始区域数据并经过修改的要素。 针对部分选定要素，已按照指定阈值对几何形状进行了概化处理，以减少大型多部分多边形中的顶点数量，提升Web服务性能。 目前每个数据集中被概化的要素不超过5个，且根据需求，每个要素的概化容差范围为1米至30米不等。 为进一步提升Web服务性能：已在可行范围内自动修复OGC（开放地理空间信息联盟）几何问题，对真实曲线进行了加密，并将数据投影至WGS 1984 Web Mercator Auxiliary Sphere投影坐标系中。 已启用同步功能，但禁用编辑功能。 本数据集的联络人邮箱为：[e-mail]