Don Johnson has both BS and MS degrees in geophysics from Michigan Technological University, making him one of a relatively small number of geophysicists working at archaeological sites with a true education in geophysics.  He has over 20 years of experience providing high-resolution, near-surface geophysical services to meet client objectives in many applications.  He specializes in archaeological mapping, unmarked grave mapping, environmental investigations, underground storage tank detection, lost well locating, and hydrologic/geologic mapping.

Don has worked all over the world. A partial list of locations where he has worked include Minnesota, North Dakota, Wisconsin, Maryland, Tennessee, Turkey, Bolivia, Ecuador, and Italy.  This picture of Don was taken during a survey at Palmitopamba, Ecuador.

He is currently working on the Silvernale site in Red Wing, Minnesota.   Silvernale is one of the earliest and largest of at least nine large village sites inhabited between ca. A.D. 950 and 1400 at the junction of the Cannon and Mississippi rivers.  He is compiling available maps and air photos to provide a consistent-scale map showing mounds and other features mapped from the late 1800's to today.  Additionally, he is conducting comprehensive magnetometer and resistance surveys to help establish site limits and to help the archaeologist plan excavation locations.

Recent projects include:

This project was undertaken as one part of a series of activities related to the realignment of Ruins Road through LA1674, at the eastern and southern boundaries of Aztec Ruins National Monument.  Don conducted geophysical investigations consisting of magnetometer and ground resistivity surveys to map archaeological features where the new road will traverse LA 1674.  Geophysical anomalies were tested with excavations by archaeologist Dr. Schirmer.

The Palmitopamba site has apparently been used for various functions prior to the Spanish Conquest.  One of these functions, and the most conspicuous, was as an Inca pucurá (fortress).  There is little information regarding the presence of Incas in the subtropical western slopes of the mountains in the northern regions of Ecuador, where this site is located, or other tropical regions of the Andes.  For this reason, the pucurá at the Palmitopamba site is of great interest.

The 2002 season was the first in which substantial investigations (including geophysical surveys and excavations) have been conducted at the site.  Don conducted magnetometer and resistance surveys over 4 terraces there.  The objective of the geophysical investigations was to help identify structures or other features that could be targeted by excavations.

St. Mary's City is the fourth permanent settlement in British North America and Maryland's first capitol.  Don conducted two separate investigations here.  One was conducted in an area called "The Triangle" and the other in the area surrounding the Brick Chapel.

 

Magnetometer and resistivity surveys were conducted at "The Triangle" and they located possible structures in a corner of the site and linear anomalies throughout the site that appear to be related to past agricultural activity or old roads.

 

GPR, resistivity, magnetometer, and metal detection surveys were conducted in the Brick Chapel area to map colonial burials and other features at the site.  Several possible burials were mapped by the investigation.

 

A magnetometer survey was conducted over and around this 19th century military fort in support of an archaeological project to identify, document, and evaluate historic properties associated with the fort.  The magnetometer data mapped several unknown structures outside the fort.  Limited testing indicates these are contemporary with the fort and may be subjected to additional investigations in the future.