The helicopter would be illegal, at least in WA, not sure about MT.
Prohibited Methods Pg. 80
4. Using aircraft: It is illegal to:
• Use an aircraft to spot, locate, or
report the location of wildlife for the
purpose of hunting. • Hunt big game on the same day you
were airborne for any purpose, except
for a regularly scheduled commercial
flight
MT is a bit less restrictive.
Airplane Spotting
Aircraft may not be used to locate big game animals for the purpose of:
• Hunting those animals during the same hunting day after a person has been airborne or;
• Providing information for another person for the purpose of hunting those animals within the
same hunting day after being airborne;
The use of unmanned aerial vehicles (UAV) for the purpose of locating, spotting or hunting
big game, upland birds or other species under the management authority of FWP during
commission-established hunting seasons is prohibited.