TxDOT’s potential archeological liability maps (PALMs) and hybrid potential archeological liability maps (HPALMs) are predictive models to aid in transportation planning and cultural resource compliance. These maps for ArcGIS present the relative likelihood for National Register of Historic Places-eligible prehistoric archeological sites to be preserved in the near surface (less than one meter) or at deeper levels in the mapped areas. The maps were developed by TxDOT's Environmental Affairs Division for cultural resource planning and compliance by TxDOT and its partners and agents. TxDOT plans to add to these as staff develops more maps.
Below are links to downloadable mapping files for the available TxDOT districts. Each zip file contains raster and vector versions of the district model, layer files containing symbolization, and supporting documentation. Review the included "Read Me" file for additional instructions.