In this GeoShort, we briefly discuss how people measure groundwater, from the fairly rudimentary (stick a measuring tape down a well) to the highly sophisticated (satellites and conductivity!). We highlight the GRACE satellites that have been used for decades to monitor and predict groundwater levels around the world. And we also briefly discuss work by future Penn State Professor Dr. Chloe Gustafson, who uses electromagnetism to measure groundwater underneath the Atlantic Ocean (see her publications here: https://scholar.google.com/citations?user=hFaSe94AAAAJ&hl=en). In summary, groundwater is awesome and measuring it can be both simple and very difficult!