When I was working for a cable TV company in houston we had some people who refused to grant us access to their backyard. A couple of landowners even pulled a gun to make the workers leave the property.
After the police were called, the police explained to the property owner that they had to grant us access.
If the land owner did not grant us access, the police would be forced to arrest the land owner, or restrain the land owner until we finished our work.
If you do not want people going on your land, do not buy land that has a right-of-way or utility easement.