A few birders and myself continued looking for the Anhinga for another 90 minutes or so to no avail. For anyone that may want to look some more, the location of the original sighting is the large pond about 300-400 yards straight west of the parking lot on the northeast corner of the property. Follow the mowed trail to the southern end of the pond for a good vantage point. I’d also recommend bug dope or long sleeves/pants to give you a little cover from the mosquitoes.
Congrats to the original ebirder that found it, fantastic bird for Iowa!
Kevin Murphy, Boone