Between September and November 2020 Lawrence University conducted a geophysical survey in the area immediately northwest of the historic Grignon Mansion. The survey was undertaken to follow up on a previous geophysical survey, conducted in 2018, that identified possible prehistoric structures in that area. A combination of high-resolution magnetic, soil resistivity, and ground penetrating radar surveys were conducted over a 40 meter by 40 meter area in anticipation of better resolving these structures. The survey identified a number of features that appear to support the results of the 2018 survey, thus strengthening the case for the presence of undisturbed prehistoric structures.
Peregrine, Peter N., "Geophysical Survey of North Kakalin Village on Wisconsin Site OU-0115, Kaukauna" (2021). Archaeological Reports. 12.