Enticed by some cheap airfares from Columbus, OH to New Orleans, Susan and I spent several days in the New Orleans area at the end of April.
Sites visited included the City Park where several Live Oaks were measured with the largest listed below.
Live Oak Quercus virginiana 13.7' x 59.4', 18.2' x 41.5'

Click on image to see its original size
18.2' x 41.5'
The above pictured Live Oak is known as "The Dueling Oak". Larry Tucei measured this tree and some other Live Oaks in a visit to the City Park in 2008.
Here is a link to his report:
http://www.nativetreesociety.org/fieldt ... isiana.htm
and
http://www.duellingoaks.com/
Also visited was the Jean Lafitte National Historic Park and Preserve. The unit visited was called the Barataria Preserve near Marrero, Jefferson Parish just south of New Orleans. The preserve has acres 23,000 acres of land and water
We strolled along the Coquille trail and boardwalk among plentifull birdl ife and a few alligators. A few heights of Bald Cypress were measured with the tallest at 80.1'. No diameter measurements were taken.
Baldcypress Taxodium distchiuium *** x 80.1'
The most impressive tree is pictured below. It is known as the "Monarch" of the Forest or Swamp. It did look impressive but partly because the surrounding trees were not impressive. It is registered Louisiana Purchase Legacy Tree. My estimated circumference judged from from the boardwalk would be in the 19-20' range.

Click on image to see its original size]
**** x 76.2'