When I saw that there was a reply to my message I hoped it was information about the Washingtons. But I'm glad to tell you where I found the 1899 taxpayers list. There is a wonderful website that has a lot of information about Tensas Parish - court records, 1860 and 1870 census records, marriages, etc. It is: www.usgwarchives.org/la/tensas/.htm
When you get there, select "Court Records" and you will see the taxpayers list.
Wish I were able to go to the courthouse and do research, but I am in California.