Traffic
In Omaha, the traffic reports are handled by two companies for the different radio and TV stations.
The only one that uses a helicopter at all is Channel One. They use the helicopter very infrequently anymore, relying instead on scanner traffic and on Live Tv Cams on the internet.
When they do have a helicopter up, and it's been several months since I heard one, they were on 455.9875. The Channel One office is downtown, and the closer you were to the office, the clearer you could hear them. Whether or not you could hear the helicopter depended on how close it was to you.
I believe the copter was housed, and took off from, the Council Bluffs airport.
Typically, you might hear the copter pilot on the afternoon times, talking to Channel One.
In the morning, you might hear "Jim" doing a live traffic broad cast. They would broadcast from the helicopter to the Tv or Radio studio on one of several frequencies in the 450 and 455 frequencies. Mainly 450.650, 450.350 and 450.800.
Good Luck!