In 1983 a Ground Positioning Unit (GPS-those things that are in cars and tell you to turn left in point five miles) were cumbersome. It took a car battery, the charge lasted only a few hours, and the unit did not work well under the forest canopy.

We used stereoscopic paired aerial photos to pinpoint our desired locations.

I’ve come across black bear, rattlesnakes, yellowjackets (wasps), lightning (where do you go to get shelter in the woods?), millennial survivalists, and other assorted hazards.

I’d have assumed it was all done by satellite these days. Do you come across many snakes? I watched David Attenborough’s fascinating programme about snakes last night.