The geocache is not at the posted coordinates. The posted coordinates is near where the 3rd Tuesday in Eldersburg Event has been held ever since it started 100 events ago, in which this geocache is celebrating the anniversary. To get the final coordinates is very simple. On the internet, find the original listing to the very first 3rd Tuesday in Eldersburg event. Enter into the Certitude below the following information in order without any spaces:
The GC code to that event, the number of attended logs, and the name of the first geocacher that posted a Will Attend
You will have to drive to the final location.

You can validate your puzzle solution with certitude.