Worked power industry long enough to get a feel for Circumference of field around lines. Ours at 345kV (Actually closer to 360) was close to eight feet radius around line, ANY item entering that zone would be affected, anything grounded got within 10-12 feet and line power would arc to ground fault. Worst I saw was Mo Dept of Conservation doing prescribed "Prairie" burns of wild fields, a few random cedars lit off with Dense Thick smoke and our lines arc faulted to ground THROUGH THE SMOKE. Lines were at low point greater than 50 feet above grade, had to be careful in summer as ACSR cable sag due to ambient heat and current flow induced heat sag would increase by as much as 3 feet. Do NOT see the need for such High Towers, have similar lines and power flows in our Gulf States areas crossing rivers used for Sea Going vessels and NOWHERE near as tall. They may be using too few towers for distances achieved and to decrease sag issues went to such extreme height.
In 1980s a combine got under the UE Portage Des Sioux power station feeders, misty foggy morning, trying to beat weather coming on with high temps for the week, lines had sagged from extreme load heating and ambient conditions some 6-8 feet, combine caught a small rise where dust in moisture laden air the power arced to the combine, driver killed, added smoke from grain oil and rubber burning the Breaker auto reclose function kept hitting the combine until the Power Supply agents shut down the line. Just UGLY!!!