NOAA's Corbin Training Center offers classes online and at the training center on OPUS Projects. manager training for Geodetic Digital Leveling, and many more.

Past Classes and their presentations
http://www.ngs.noaa.gov/corbin/past_classes.shtml

and Upcoming Classes
http://www.ngs.noaa.gov/corbin/calendar.shtml

http://www.bls.gov/oco/ocos040.htm

http://www.surveyingcareer.com/

http://www.profsurv.com/magazine/article.aspx?i=70959

Their standard unit of measurement is the vara (33 1/3”). They also use a League, a Labor, a Sitio in their descriptions. What is most interesting is that land was formed under Spanish Law(1720-1821), then Mexican law(1821-1836), then Texas as a Sovereign Nation(1836-1845), then as part of the US. With each change they respected the previous laws so when you look at a deed, you have to see what year it was granted.

-Derek Zeman

These areas have some evidence of cypress logging but I beleive many of the trees are very old like the attached live oak pic taken last year.

-Joe Stokes

Witness Trees, what others think about them.

Witness trees are living links to our history
http://www.caller.com/news/2011/mar/30/witness-trees-are-living-links-to-our-history/

Witness Trees
http://www.witnesstrees.org/home.html

Civil War Witness Trees
http://thewitnesstree.net/witness-trees.html
http://www.bivouacbooks.com/bbv2i1s4.htm

http://oxfordlandsurveying.com/what-is-land-surveyor/

http://www.npca.org/parks/mount-rushmore-national-memorial.html?adwords=1&gclid=CMmo0MTL-q0CFUSo4AodGgsQvQ

http://www.vfcc.edu/aboutVFCC/?p=showthinkAboutIt&id=89