Geography

A little knowledge is a dangerous thing.

There are a lot of bridges over the Thallahatchie Bridge. I don't know why the one in Money, Mississippi is suggested as the one in the song, except that it is just a few miles from where Bobbie Gentry grew up in Greenwood.

And now I have read a suggestion that the Thallahatchie Bridge in the song was farther northeast, where the Thallahatchie river is in the highlands of the Choctaw Ridge.

This page http://jjmccullough.com/billyjoe.htm claims it happens near Batesville, Mississippi:

"An internet source uncovered a valuable old map that clearly marks the delta and the place where the Tallahatchie River intersects Choctaw Ridge. This would put the events in and around Batesville, Mississippi. From Robert Pollack's description of his scanned map:

I like this map because I have seen no other of Panola County, and because of the clarity with which it indicates the Delta, which is ambiguous on most maps though it is not ambiguous when driving into or out of it.

Also, I learned from this map that Choctaw Ridge names the border separating the Delta from the Hills. This realization shed new light on the Bobbie Gentry song, in that a) the line "Nothin' ever comes to no good up on Choctaw Ridge" could reflect the historic cultural antagonism between the Delta whites and "Rednecks" from the hills, and that b) the central event of the song presumably occurs in Panola County, as the Tallahatchie River crosses Choctaw Ridge here, and thus the Tallahatchie Bridge named in the song is presumably here as well.
This seems to incontrovertibly narrow down the non-fictional location of this fictional event. Thus the Tallahatchie Bridge could refer to any bridge that crosses the Tallahatchie River."

But on the other hand, Bobbie Gentry would have known that Money, Mississippi's other claim to fame was what was put into the Thallahatchie River on August 28, 1955, so possibly the bridge in the song was supposed to be the one in Money.