Earlier today, I found the 10th different CASC letterbox cache for the Spring Fling happening at the beginning of May, so I was pretty sure I would be qualified for this one. Yeah, I don't shy away from letterbox caches and I'm working on filling my calendar grid with them. I now have 215 different dates filled.
Webfoot has used Project-GC to see if they qualified for this challenge and they did.
"Find at least 1 Letterbox in 25 US Counties." Qualifying 36 / 25, PASSED