Hi Brad.
CNBG are for southern, warm waters. Here in Colorado, even "northern" BG don't thrive in some of our cooler BOWs. As an example, my pond, at 6500 feet above sea level, and fed by irrigation water from the Dolores River, seems to be fine for GSF, YP, trout all summer, LMB. But BG have been stocked on at least two occasions and have not persisted.

There are numerous references to the requirements of both fish in the archives which make fascinating reading.
Roger