In several eminent domain cases I have worked on, First Energy has used extremely broad language to appropriate tree clearance rights on "adjacent land."  Here is the language they seek to appropriate in their petitions:

Plaintiffs shall also have the full authority and right, in their sole discretion, to trim, remove, clear, keep clear, and otherwise control any or al trees or vegetation adjacent to said right of way that, in the opinion of Plaintiffs, may interefere or threaten to interfere with the construction, operation, maintenance, or repair of Plaintiffs' facilities along said right of way.

There is case law in Ohio that says that "adjacent to" is an inadequate description of the property in an appropriations case - the court called it "vague and broad" and "unenforceable as written."  When pressed, First Energy provided a more definite description of the property involved in the tree clearance portion of the easement - if was an additional 80 feet on each side of the 60 feet easement for the transmission corridor. 

Not only is that more land than most would expect, the incredibly broad language leaves the determination of what a danger tree is completely up to First Energy.  If you don't agree, you would have to file a complaint with the Public Utilities Commission of Ohio.