The high voltage power cut through ELG common land is a Duke Energy easement. They like to spray herbicides under the lines, to keep trees from growing up to threaten the wires. ELG has preferred that they mow. In order to keep them mowing instead of spraying, the most important thing is to display official no-spray signs.
Duke Energy does maintain a database of owner preferences, but this is the process: before spraying, they come and look at the property. If your sign is down, or even blocked by weeds, they assume you have changed your mind and take you out of the no-spray database.
The signs are available from a print shop near Sportsplex in Hillsborough. As of 2017, Larry has a small pile of them from 2011. The order form is shown below. The signs are cheaply made and fall apart in a few years. In 2017, a Duke Energy rep suggested asking the sign shop if they can make more permanent signs, maybe on metal.
You can see the results of spraying where the power cut intersects Borland Road. It's really not that bad looking. Duke Energy says that their selective spraying of small trees is kinder to the environment than indiscriminate mowing, and encourages the development of a "prarie ecosystem" in the power cut.
On their 2017 visit, they showed up with a team of 15 people, all with backpack sprayers. After being stopped at Baer Hill Road, the team walked down the woods edge to see if they could find another parcel where they would be allowed to spray. The moral is that you have to go above and beyond to make sure your no-spray wishes are unmistakable.
Duke pays great lip service to customer choice, etc., but their processes change over time and are not worth documenting here. Next time this becomes a crisis, it will have to be figured out fresh, starting at the main customer service line.