GeoVelo noticed the survey bearings on the 97 mile road plat were often in error and so began looking for potential sources of that error. Geological ground based magnetic deflection was identified as a possible cause. In addition, the survey practices at the time did not always include recording the earth local magnetic variance from True North. So GeoVelo began to work on the magnetic declination issue when transcribing the calls on the 97 mile road plat.
