Hi, I am not sure if this will help you out or not, but on a cd called Colorado Marriages 1858-1939, an index compiled by The Denver Public Library, c2004 Colorado Genealogical Society.

Duemcke, Albert - Nippert, Nellie - 22 Jul 1890 - Denver 9492
Duemcke, Bertha - Janssen, Nick M. - 18 Jun 1891 - Denver 11298
Duemke, Bertha - Janssen, Nick M. - 18 Jun 1891 - Denver 11298

The County listed is the county the marriage was registered in and may not be the county they married in.