The 1920 Clarke County, Iowa, US Federal Census contains 
~230 pages (census images) in Enumeration Districts 35 to 47. 

These images donated by the Allen County Public Library (Indiana).
Scanned images have been reformatted for use in the USGenweb Archives 
by Alice Warner Brosey. 

In the folder for the census image files:
http://www.usgwarchives.net/ia/clarke/census/1920/
the name of each census-image-file is the number of the Enumeration 
District followed by a dash and then the sheet number for that page. 
Example: Sheet 3A of Enumeration District 16, is named ed16-03a.jpg
The image files are in subfolder by enumeration district.

The following list shows the 1920 Clarke County districts and Enumeration Districts.

   ---  ------------------------------------
   ED   DISTRICT DESCRIPTION                SHEETS
   ---  ------------------------------------
   35   Doyle Township                       1a-6b
   ""   Doyle Township: Hopeville Town       7a-8a 
   36   Franklin Township                    1a-6b
   37   Fremont Township                     1a-6a
   38   Green Bay Township                   1a-6b
   39   Woodburn Town                        1a-4b
   ""   Jackson Township                     5a-10a
   40   Knox Township                        1a-6b
   41   Liberty Township                     1a-8a
   42   Madison Township                     1a-5a
   43   Osceola Township                     1a-6b
   ""   Clarke County Home                   7a
   44   Osceola Twp: Osceola City, 1st Ward  1a-11a
   ""   Osceola Twp: Osceola City, 2nd Ward  11b-17b
   45   Osceola Twp: Osceola City, 3rd Ward  1a-11a
   46   Troy Township: Murray Town           1a-9a
   ""   Troy Township                        10a-15a
   47   Washington Township                  1a-5b
   ""   Ward Township                        6a-10a