If your talking about the Omega tower outside LaMoure there are no nets. The nets would have to be close to 3/4 mile across. I use to drive the perimeter road all the time till 911 when they closed all access to the base. I can honestly say,I seen very few birds dead from hitting the guy wires. And there are lots of them and there big. Close to 2 inch in diameter.
Wrong we had netting under a large segment of that tower perhaps before your time. We had a collection of study skins from those strikes. A study doesn't require the entire area to have nets 10% will give an accurate statistical analysis as long as it is an accurate representation of high and low elevation wires that span different habitats. Also many species migrate at different above ground elevations. Some migrate all times of day, some only diurnal, some only nocturnal, and many follow river valleys right where the Omega tower is situated.
Oh by the way the nets were in place a couple years after the tower was finished, whenever that was. Nets were installed I think in 1971. I believe they were military surplus nets. The nets revealed thousands of birds strike those cables. A segment of society doesn't want to hear that much like many dont want to hear that a study done in Michigan revealed that the greatest danger to paserine bird there is house cats, and we're talking millions per year.
Also my point was you don't see them, even if you get out and search for them. I'll bet local predators still enjoy the feathered buffet.