Why not? Use the Import function, and select "import at current location". All of your existing folders will be displayed, as is, in the Folder pane.
Thanks. I figured out what was hanging me up. I did what you suggest, and selected my \LatestDownloads folder. However, as there were no actual image files in that folder, when I clicked OPEN, it simply opened the folder and took me down one level. When I repeated the process, it finally took me to some image files, but when I hit IMPORT, the higher level folders did not get imported.
Finally, it occurred to me to *not* click on OPEN, but rather to click on the SELECTED button (duh!). As I write this, LR is doing exactly what I wanted.