Use the readRDS() function for .rds files or the sf package to load GeoPackages. Specialized packages like GADMTools can further streamline the process.
Downloads the global database (file sizes are massive). Select your preferred GIS format (GeoPackage or Shapefile). Option 2: University Repository (UC Davis)
You can choose to download the entire world or specific country datasets: By Country : Navigate to the Country Download page download gadm data version 36 work
To successfully and make it work , follow this final checklist:
| Field Name | Data Type | Description | | :--- | :--- | :--- | | GID_i | String | Preferred unique ID of the administrative unit (e.g., AFG.1_1) | | ID_i | Integer | Alternative unique identifier for the level | | NAME_i | String | Official name in Latin script | | VARNAME_i | String | Alternative names, separated by pipes ( | ) | | NL_NAME_i | String | Official name in non-Latin script (e.g., Arabic, Chinese) | | HASC_i | String | Hierarchical Administrative Subdivision Code | | CC_i | String | Unique identifier used within the country | | TYPE_i | String | Administrative type in the local language | | ENGTYPE_i | String | Administrative type in English | | VALIDFR_i | String | Date from which the data is known to have started (YYYY-MM-DD) | | VALIDTO_i | String | Date until which the data is valid (YYYY-MM-DD) | | REMARKS_i | String | Comments about edits or historical changes | Use the readRDS() function for
GADM attribute tables include a GID_0 (country code), GID_1 (state ID), and NAME_1 (state name). Use GID_1 for reliable joins.
GADM 3.6 boundaries are high-resolution (often >1 MB per province). Use simplification before serving tiles: Select your preferred GIS format (GeoPackage or Shapefile)
Downloading by country is the most efficient and recommended approach, especially if you only need data for a specific nation or region. The global files are very large and may take a long time to download.