Whoa...! A mile? That must be some air-cannon. Who's the target? Do you need to track this thing live in flight (NASA), or find it's impact after the fact? You know the transmitter on/in the pumkin would need to be very solid to survive the launch (search for something in the model rocket telemetry/recovery department), and likely to be destroyed on impact unless its over water.
Remember seeing some kind of anual competition like this, except it wasn't that long range, maybe couple of yards.
Oh, no offense... But from previous threads and the general paranoia... Your not a terrorist are you? And this isn't going to be pointed toward Canada, right?