On Google Books, the title "Louisiana as it is: a geographical and topographical description of the State" by Samuel Henry Lockett, Lauren C. Post, (page 13), mentions Gilmore's Ferry, Catahoula, and a Mr. and Mrs. Gilmore, and other ferries in the area.
Also on Google books, "Louisiana place names of Indian origin: a collection of words" by William Alexander Read mentions Bayou Funny Louis.
Article on MSN:
Late inspections of bridges put travelers at risk
At least 17,000 spans didn't get a two-year checkup
Bridges reported past two years since their last inspection include the obscure, crossing the Dangerous River in Alaska and Bayou Funny Louis in Louisiana, and the heavily traveled, carrying traffic on Interstate 5 in Los Angeles and Cicero Avenue in Chicago.
If you enter Bayou Funny Louis into Google maps, you'll see where it is and possibly determine whether it is on/near your ancestor's property.