Though never common at Pheasant Branch Conservancy, here are my eBird dates for single (mostly) or double sightings of Grasshopper Sparrow (Ammodramus savannarum):
2013-07-13
2013-07-11
2013-06-28
2012-05-31
2012-05-21
2011-06-21
2011-06-05
2008-07-19
2007-05-25
The above photograph was taken in 2004. I'm fairly certain I had encountered them at the conservancy in 2005 and 2006 prior to using eBird to document my avian observations. Though there is suitable habitat for this grassland species at Pheasant Branch's prairie, I have not observed them there since the summer of 2013. Though this is a more imperiled bird than the Clay-colored Sparrow, it's interesting that its disappearance coincides with the last of that species.
Grasshopper Sparrow © 2017 Mike McDowell