County Boundaries

Database of Montana Counties created to be coincident with the Montana Cadastral Parcel Boundaries. Where county boundaries are coincident with public land survey section lines, they were copied from the BLM's Geographic Coordinate Database (GCDB). If boundaries were not coincident with GCDB lines, they were digitized on screen from 1:24,000 scale Geological Survey Digital Raster Graphics (DRGs). County Boundaries will change as the GCDB is adjusted by the BLM and those data are imported into the Cadastral Data Model. Metadata本数据集为蒙大拿州县界数据库，其边界与蒙大拿州地籍宗地边界（Montana Cadastral Parcel Boundaries）完全一致。当县界与公共土地测量分区线重合时，其边界数据直接取自美国土地管理局（Bureau of Land Management, BLM）的地理坐标数据库（Geographic Coordinate Database, GCDB）。若县界未与GCDB分区线重合，则通过屏幕数字化1:24000比例尺的美国地质调查局数字栅格图（Digital Raster Graphics, DRGs）获取边界数据。随着美国土地管理局对GCDB进行调整并将更新后的数据导入地籍数据模型（Cadastral Data Model），本数据集的县界信息也将同步更新。元数据（Metadata）