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Geophysical survey and excavations from 2010–2016 at Lawrenz Gun Club (11CS4), a late pre-Columbian village located in the central Illinois River valley in Illinois, identified 10 mounds, a central plaza, and dozens of structures enclosed within a stout 10 hectare bastioned palisade. Nineteen radiocarbon (14C) measurements were taken from single entities of wood charcoal, short-lived plants, and animal bones. A site chronology has been constructed using a Bayesian approach that considers the stratigraphic contexts and feature formation processes. The village was host to hundreds of years of continuous human activity during the Mississippi Period. Mississippian activity at the site is estimated to have begun incal AD 990–1165 (95% probability), ended incal AD 1295–1450 (95% probability), and lasted150–420 yr (95% probability)in the primary Bayesian model with similar results obtained in two alternative models. The palisade is estimated to have been constructed incal AD 1150–1230 (95% probability)and was continuously repaired and rebuilt for15–125 yr (95% probability), probably for40–85 yr (68% probability). Comparison to other studies demonstrates that the bastioned palisade at Lawrenz was one of the earliest constructed in the midcontinental United States.

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Mississippian mounds in the south‐eastern and mid‐continental United States often contain multiple construction stages and a diverse array of features. Investigating mound construction with excavation is expensive, logistically challenging, and sometimes politically impossible. Three mounds at the Angel site (12VG1), a Mississippian village (ca ad 1100–1450) in the lower Ohio River Valley, were investigated with non‐invasive geophysical and minimally invasive geoarchaeological methods. We compare the efficacy of two different ground‐penetrating radar (GPR) antenna frequencies (250 and 500 MHz) for detecting elements of mound construction previously identified with solid‐earth cores, magnetometry, and electrical resistance tomography. Solid‐earth cores provide stratigraphic information about mound layers and construction soils and materials with low horizontal spatial resolution. Surface magnetometry provides information on shallow features, such as buried building walls and floors at high resolution, but little information about depth. Radar profiles taken with 500 MHz and 250 MHz antennae were evaluated to determine which antenna frequencies are most suitable for detecting features and strata that had been documented using the other methods. Utilizing the solid‐earth cores for velocity correlations, the 500 MHz antenna provided the most useful information about prehistoric structures near the mound surface, but was limited by its relatively shallow penetration depth. The 250 MHz antenna was not able to resolve shallow features as clearly as the 500 MHz antenna. However, it was able to detect possible interior mound platforms and features, although without providing many details about possible buried structures. In combination, GPR, solid‐earth cores, and magnetometry provided new information about the construction of mounds at the Angel site.