This cache was placed to commemorate the launch of the first of the GPS III satellites! As geocachers, we rely on these GPS satellites for our hobby, and the new GPS satellites will be 3 times more accurate for civilians (once there is a full constellation of these babies).
The first GPS III satellite launched on December 23, 2018. It is the 74th GPS satellite vehicle (SV) and is the 73rd to launch (there was one “oops”).
Although GPS supports all sorts of applications, obviously the most important one is geocaching! So get out there and use that new satellite!