I've seen the DC-10's that are converted into tankers, they've been here in Boise a few times. I"ve also seen the Bae-146's and there is an MD-83 tanker as well. The National Interagency Fire Center in Boise often has them parked on the ramp.
Here's a pic of the 747-400:
Areoflite based in Spokane tells me it's a call to call but 2 hours to refeul and take off to the GPS Lat/Long I do carve the Bae 146 tanker along with others...