Micheal
I have not found exactly the resources I used before but I have found several resources on the subject albeit all in French:
http://dictionnaire.sensagent.com/A...7aise/fr-fr/https://books.google.nl/books?id=se...1899&f=falsehttp://www.cosmovisions.com/ChronoS...Francais.htmhttp://www.webafriqa.net/library/hi...duction.htmlhttp://www.clio.fr/chronologie/chro...gie_mali.asp Three of these resources concur on a detailed description of how French Sudan was broken up in 1899: which cercles - French administrative units - were transferred to what countries and which cercles were to form the civil (1) and military (2) territories. This suggests that the French by 1899 had mapped out this part of French West Africa in considerable detail and even had divided it into administrative units. Thus a more detailed map than for example the one in The Stampatlas would seem entirely possible.
What these resources also seem to concur on is that the civil territory created was attached to Senegal. A delegate was appointed - William Ponty as mentioned earlier - that reported to the lieutenant governor of Senegal. At the same time the budget for this territory was administered directly by the governor general of French West Africa. The military districts also resorted under the governor general. This all too complex situation was in 1902 remedied when all of Senegambie & Niger came directly under the under the governor general. When in 1904 Upper Senegal and Niger was formed it became a colony with its own lieutenant governor.