I have a folder for each of the fifty states with each folder containing between 200 and 40,000 html files.   I am using the code below to generate a sitemap.aspx in each folder.  All of the filenames in each folder start with "Link".

foreach (string file in Directory.GetFiles(Server.MapPath("/State/AK/"), "Link*"))

I only need the folder sitemap to create the hyperlinks for webcrawlers.  An example is .../State/AK/Sitemap.aspx   It generates the links just fine and produces the below hyperlinks:

LinksAKANCHORAGE.html
LinksAKANCHORAGE1716.html
LinksAKANCHORAGE1734.html
LinksAKANCHORAGE1749.html
LinksAKANCHORAGE1760.html
LinksAKANCHORAGE1912.html
LinksAKANCHORAGE1913.html
LinksAKANCHORAGE2001.html
LinksAKBARROW.html

MY QUESTIONS:  1) Is creating individual sitemaps in each folder appropriate and 2) do I need to create another sitemap in the root that contains links to the individual folder specific sitemaps?  I am not using this for navigation only to help the webcrawlers find these dynamically generated html pages.

Thank you

 According to your description, do you just want to create a page that can navigate to the thousands of HTML files? If so, I suggest just one aspx in the root file is OK. Just include the sub folder information in the link. I only give a simple sample. If I have any misunderstand, please let me know.

        string strRootPath = Server.MapPath("Your root folder");
        string[] strSubPaths = Directory.GetDirectories(strRootPath);

        foreach (string strSubFolder in strSubPaths)
        {
            string[] files = Directory.GetFiles(strSubFolder, "Link*");
            foreach (string file in files)
            {
                string strLink = strSubFolder + "/" + file;
                //TODO, Generate your link.
            }
        }