Go to Edit > Preferences > General and enter 1 in the Keyboard Increment box. Select the path created in the previous step and make two copies in front (Control + C > Control + F > Control + F).
Select the top copy and hit the down arrow twice. Reselect both copies and click on the Minus Front button from the Pathfinder panel. Turn the resulting group of shapes into a compound path and fill it with R=140 G=135 B=120.