As someone from the northeast, I have been lucky enough to take 2 from a prone position with a Harris Bipod and a small dry bag used as a rear rest.
1st at 346 yds at 5:30 pm on Day 10 of a 10 day hunt and 13 miles from base camp after pulling an all nighter on the same ram the day before...arrived back at the tent at 8am the next morning...plane arrived at 10am with the next hunter.
2nd at 415 yds after running about 300 yds after getting winded...could not get steady when finally got set up when rams were at 350 yds...everything came together when the ram stopped, turned to look back and I heard my guide say, "415" in a confident voice.
Great memories. Good luck!