I'm from the Denver area, and I would suggest you try this site http://www.denverhealth.org/portal/Professionals/CareerCenter/JobSearch/tabid/328/Default.aspx. Those are pretty close to competitive wages for the area (sorry to see that these wages haven't changed since 2004, so things have "flattened out", again).

This is the search result I received for RNs in L&D (and they do hire new grads for OB):

5/8/2006 RN - Registered Nurse 6439 Labor & Delivery Rotates/36 $23.71?$30.82
12/16/2005 RN - Registered Nurse 5638 Labor & Delivery Rotates/24 $23.71?$30.82
8/22/2005 RN - Registered Nurse 5094 Labor & Delivery Rotates/36 $23.71?$30.82
5/24/2005 RN Intermittent Plan B 4654 Mom/Baby Unit Intermittent/0 $31.00?$31.00

This is pretty typical for the Denver area. University, Exempla & Centura pay within about $.50 of these ranges, depending on experience. You will see a big difference in shift differentials with Centura, where I made up to $7.50/hour for weekend nights.