"I looked at rock type (Sandstone), color (red and white - no black streaks like found on higher cliffs in Utah), shape (more rounded indicating a more exposed area and erosion), the texture of the canyon floor (flat rock vs sloped indicating higher up in a watershed with infrequent water), and the larger cliff/mesa in the upper background of one of the photos. I took all that and lined it up with the flight time and flight path of the helicopter - earlier in the morning taking off from Monticello, UT and flying almost directly north before going off radar (usually indicating it dropped below radar scan altitude. From there, I know I am looking for a south/east facing canyon with rounded red/white rock, most likely close to the base of a larger cliff/mesa, most likely closer to the top of a watershed, and with a suitable flat area for an AS350 helicopter to land. Took about 30 minutes of random checks around the Green River/Colorado River junction before finding similar terrain. From there it took another 15 minutes to find the exact canyon. Yes... I'm a freak."
With the risk of sounding like downplaying it, I think the crucial part here is the potential range of the helicopter, which is fairly limited with the information given (start location, time etc.), and the fact they can walk in from somewhere flat enough to land the helicopter.
The geological part is nice but not necessary (you just need to be able to tell the colors of rocks).
"I looked at rock type (Sandstone), color (red and white - no black streaks like found on higher cliffs in Utah), shape (more rounded indicating a more exposed area and erosion), the texture of the canyon floor (flat rock vs sloped indicating higher up in a watershed with infrequent water), and the larger cliff/mesa in the upper background of one of the photos. I took all that and lined it up with the flight time and flight path of the helicopter - earlier in the morning taking off from Monticello, UT and flying almost directly north before going off radar (usually indicating it dropped below radar scan altitude. From there, I know I am looking for a south/east facing canyon with rounded red/white rock, most likely close to the base of a larger cliff/mesa, most likely closer to the top of a watershed, and with a suitable flat area for an AS350 helicopter to land. Took about 30 minutes of random checks around the Green River/Colorado River junction before finding similar terrain. From there it took another 15 minutes to find the exact canyon. Yes... I'm a freak."
u/Bear__Fucker