From Three Forks, Montana, we traversed south with the USGS mobile ground magnetometer to the Wind River Range, west of Lander, Wyoming. While there, we stayed in Atlantic City, Wyoming, which was a large log boarding house run by Aunt Ellen, who was 95 years old at the time. She had opened the boarding house just after the turn of the 20th century, just before the last gold rush in the area. Several aging prospectors still lived up there, mostly in retirement but still fossicking for whatever gold they could find.
We asked Aunt Ellen why they had named the place ‘Atlantic City’. Looking at us as if we must be dull of mind, she snapped, “Because it’s on the Atlantic side of the continental divide, of course!”
Late one night I awoke to what seemed like a thunderstorm. I heard a loud cracking and rumbling, followed by what seemed like a mighty long shaking, for a thunderstorm. Later I learned that what I had felt was the shock of the 1959 Yellowstone earthquake, that caused a massive landslide and dammed the Madison river, forming Quake Lake.
After traversing part of the old Mormon trail and getting “Shtook in de mood,” as an old immigrant prospector put it, our project ended suddenly. The magnetometer sensor came loose from its mounting and smashed to bits against the side of the box housing it.
We had nothing to do, then, but to head back to the Menlo Park office. It was time for me to go back to Minneapolis and write my Master’s thesis.
Epilogue: The trailer was never used again, but the project went on. Years later, on a return trip from Australia, I saw the new US Geological Survey mobile ground magnetometer, a well-engineered truck with the magnetometer sensor mounted on a short boom projecting from the back. Further research had optimized the sensor location to minimize the magnetic field influence from the truck.
The mobile ground magnetometer project was a great start for my geophysical career. I used data that I had acquired from traversing as the central part of my Master’s thesis.