Are they usually mid-summer? I am sure I am like a lot of people who work during the day or have plenty of stuff to do when I don't, so night fishing works well and plus it is usually the best time to fish!
I wonder if a annual summer night tournament could be set-up through DOW or the park supervisor at Chatfield, Bear Creek or some other reservoir that is normally shut down at dark. They could still make money at the gate and maybe a fee for having rangers present for it.
...........or maybe I am crazy and this is wishful thinking!