In the fall of 2018, a new series of Challenge Caches was started in Michigan, beginning with Benzie County. As of November, 2020, the number of counties covered by this challenge has grown to 68.
The rules of the challenges are, you can find cache and write your name in the log any time but in order to qualify for a find, you must have already found 100 other caches in that county. If you don't yet qualify, your log must be a "write note". To find out if you qualify, run the challenge checker found on each cache page. Capture the results from the checker, like this, and add it to your found log: