Dan Horgen is an OSA Research Archaeologist who has conducted and assisted in numerous archaeological surveys and excavation projects in Iowa and adjacent states since 2001. He currently helps manage the OSA’s in-house lithic raw material assemblage and coauthored the OSA’s Lithic Raw Material Assemblage web page.

Warren Davis is a research archaeologist at the OSA, conducting archaeological research for contract-funded projects that includes background historic research, field surveys and excavations, and report writing.

Angela Collins has been conducting archaeology in Iowa since 2001. Her specialized skills involve material analysis with pXRF and ceramic petrography, as well as aerial thermography utilizing a small uncrewed aerial system (drone) as an FAA-licensed drone pilot.

At OSA, Angela leads archaeological field surveys and excavations, prepares National Register of Historic Places nominations, and conducts research on various precontact and postcontact topics. She is an artifact illustrator, graphic artist, website designer, and digital publisher for the OSA, producing numerous posters, brochures, and booklets, as well as editions of the OSA Report Series.