We had a situation here in Cape Town where there are goverment agencies, private organisations, and loads of clubs all with a SAR element. It took a while, and plenty of politics, till they formed WSAR which manages the whole thing to keep things simple.
One Rescue Manager on duty. One phone number. One set of rules. They assess a situation then call however many guys they need from each discipline (Hi angle, climbers, 4x4, paramedic, etc etc). The guys get called in in phases as well. (The two rescues I've done I was in the second phase, 1st phase were already in the field, 3rd phase got stood down)
It keeps things organised, keeps the rescue scene uncluttered, and more importantly controls egos. The hi angle guys tnd to enjoy the limelight

eepwall:
Texas each county sheriff is responsable for operations
When you take a close peek at the law here the local cop is in charge. The unwritten policy though is that if the cop gets uppitty then it's downtools till he get's the message and gets out the way.