To remove the collar from USGS DRGs, open the Control Center (found on the toolbar and under the Tools menu), highlight the DRG(s) that you want to remove the collar from, and select the Options button. Go to the Cropping tab of the dialog that appears and select the Automatically Crop DRG-style Collar option and press OK. The collar should now be removed from the selected DRG(s).

If for some reason the collar was not correctly removed, you may need to specify the collar bounds manually. To do this, press the Options button again and go to the Cropping tab and manually specify a boundary to crop the collar to.