CRJ200 First Officer experiences a gear disagree caution message after takeoff. QRH procedures are complied with and Dispatch is contacted when the procedure is unsuccessful. A second attempt at correcting the problem using the QRH procedure is also unsuccessful and the flight returns to the departure airport for an uneventful landing after burning down to landing weight.

Narrative

Took off and received a gear disagree caution message. Told ATC and leveled off at 5;000 FT and got radar vectors. I flew the plane and took the radios while the Captain ran the QRH. QRH did not resolve problem. Captain contacted Dispatch and Maintenance and discussed what we should do. I tried to listen; but missed most of the conversation while listening to ATC while getting vectors. At some point Captain said he wanted to run the QRH again. He did; and it still did not resolve the problem. I'm not sure when that was in the process. I asked the Captain what Dispatch and Maintenance had to say and he said that they just had some standard questions about the gear disagree warning message and we will be returning. ATC declared an emergency for us and had fire and rescue trucks waiting. We discussed the possibility of losing nose wheel steering when we landed and I asked the Captain if he wanted to land. He said that he had confidence in my ability to handle the landing. We waited until we were under the max landing weight; and then landed with no other problems. High workload for Captain. I tried to assist him as much as possible. Communication between pilots is essential. What a pilot is doing and what he is asked to do by Maintenance. I should have asked if Maintenance had suggested to run the QRH again or if this was a PIC decision.