Early on in the story we learn that Jackie can speak and she can read. She gets Michael to find everything written down in the labs and brings them to her to read. She is on a mission to learn something but is unwilling to let Michael in on it.
She learns of an elephant sanctuary in Tennessee and decides she want to find the herd that must be there. Together they travel south along the Mississippi to the Ohio river, avoiding dangers and looking for a way across into Tennessee. All the bridges have been destroyed.
The dangers increase when they make their way across the Ohio river and find their way to their destination.
I had a bit of fun reading this by following their route using Google Maps. You certainly got the sense of how large and imposing the rivers are and how big the bridges are, or were, in the case of the story.
In the end I enjoyed the story. The talking elephant part was an easy thing to suspend my disbelief.
The authors website is HERE
His bibliography is HERE
The story was originally published in Asimov's April-May 2010 issue.