After reading a recent article in the journal Groundwater by Dr. Fred Molz (2017) regarding the history of digital computer modeling of groundwater systems, INTERA President and CEO, Dr. Marsh Lavenue, realized part of the story was missing. In a Letter to the Editor of Groundwater, Dr. Lavenue provides written comments on the contributions that INTERA, and specifically the company’s founder, Dr. Ronald B. Lantz, made in bringing digital computer modeling technology from the petroleum engineering industry into hydrogeology. An abbreviated version of Dr. Lavenue’s comments appears in the January 2018 edition of Groundwater, and his complete response is provided here.