While you are performing a typical property survey or topographic survey, try to locate occupation lines. You might ask, “What is an occupation line?” Good question. If you do not understand what your boss has asked you to do, humbly ask what they is talking about. Otherwise, you walk out the door and hope to shout out or call out to a friend. You are an apprentice and the master artisan wants to teach you because it raises the quality of the work they do.

Many people who know nothing about land surveying have heard the term ‘adverse possession.’ There are five important conditions which must be met to prove a person owns land by ‘adverse possession.’ Even if they meet all five, they might not own the land once the courts are done contemplating the case. One of the conditions is that the possession of the land be ‘outright and notorious.’ This means it is obvious to the public that the land is owned by the person seeking ownership by adverse possession. This brings us to occupation lines.

When you were a child sitting in the backseat of the car, did you ever wish for or mark an imaginary line in the seat to divide it between you and a sibling? You were creating an occupation line. Vocally you may have expressed, This side of the line is my side. When a property owner makes this physical statement, they use fences, walls, tree rows, curbs, driveways, stone rows, and steel pins and pipes sticking up along the line.  A sign might say "keep out" but I think the best bet is a nice sturdy fence.

In Pennsylvania, it must exist for 21 years and one must prove it was there for the entire length of that time.

Few surveys end up in adverse possession claims, but you should still locate lines of possession during your survey. Twenty-five years ago, my boss sent me out to a quarter acre lot survey in Phoenixville, and I started the survey by rough chaining and looking for pins. Every lot had a chain link fence. One of the neighbors came out to tell me he owned a lot 75 feet wide. He then looked down at my tape and saw my rodman was holding the end on one of his side fences as I stretched it across to the one where we were standing. The reading on the tape was 70. He asked, “Where’s my five feet?”

My reply was, “I don’t know.”

He was very upset and since I had been measuring up and down the block from fence to fence, I knew there was a problem of 5 feet in the block. I left the site, returned to the office, and explained my rough measurements to the boss who was a Cracker Jack land surveyor. 

He said, “That jobs dead, forget about it.”

He then gave me another survey to perform. He did explain that owners of small lots are not going to spend the money it would take to resolve such an issue, and it was better for my boss to forget about the hour and a half. He was a good man to work for and taught me a lot about the business side of land surveying.

At the survey where I was on another day, I observed some of the various types of occupation lines and will show you photos and try to explain the nature of each. You can locate these simply by eyeing yourself onto the line of a fence or tree row if it was projected over a sidewalk or curb. The office people will be entering deeds and your fieldwork. Having a line of possession match their calculated line gives them confidence in their decisions.

Earlier in the day, I accompanied my apprentice on a survey at which he did not find any corners. It proved to be a good opportunity for me to show him how I look for corners. We found four out of five of our corner markers plus four corners for the adjoining property owners. I also explained that had we not found any corners, he should locate the fences and road centerline so we could rough in the deeds and then return to look for monuments. During the winter in Pennsylvania, it is difficult to shovel to find monuments since the ground often is hard and frozen. If you can get within a foot it’s a tremendous help.


In the above photo, you can see the fence dividing the property I was surveying and the next site. My client erected this fence and so the posts should be on his property and the good side of the fence is what the neighbor views. The face of the good side should be either on the property line, or just of the property line and on my client’s tract.

This photo shows the front one of the four twins on the street where I am surveying. During the course of the survey, I located the outside corners of our house and several of the twins along our road. You could measure between the doors and locate the party wall, but I chose to locate the outer building corners and split the distance between the locations. I did not ever see a property corner for any of the lots with the twin houses. If you had access to the inside wall it is a good idea to check to see that the center of the party wall is where you believe it is. Remember, though the builder intended to put the wall on the line, he may have chosen to act differently. You want to limit your assumptions in your work. I was once told the word assume is made up of three words: ass, u, and me.


Here you see a shared brick walkway between two twin houses. It's painfully obvious that the brick was set by the person on the right, and they wanted to be clear where the property line exists. Using a line of brick set sideways, they made a good line of occupation. For starters, I would consider the left side of the dividing brick to be the property line.

brick walkway

Someone took care to set the brick up in this fashion, and I would consider using the line of bricks as a property line until it is disproven. This line may have been set using a split of the two side corners of the twins. Using these type of occupation lines, you can get close and consider the weight of their locations.

occupational line features

Another photo (above) has several occupation line features. You can see how the sidewalk jogs back a few feet from the back of curb line. The block walls are of different ages and materials. The wall on the right is obviously older and, generally, a new wall will be constructed to match the other wall. Both the old wall and the step in the sidewalk are on the same line. You do not necessarily have to locate the wall since it is lined up with the crack in the sidewalk. By locating the crack and labeling it OL, you will tell office staff that it is a location shot possibly on the property line. When searching for property corners, they may be in the hedgerow, at the right of way line, the top of wall, bottom of wall, back of curb, a drill hole or cross cut in the sidewalk, or a drill hole in the curb line.                    

Here is an example of an old Hilti nail in the curb. This was found by "eyeing" in the property line and guessing where it might cross the curb. I once worked for this company that set the nail and know they love their Hilti gun. Having seen their company name on the old subdivision plan, I kept my eyes open for nails in the curb. Sometimes there are pins at the right of way line, sometimes not.

You could say that I found this nail by looking at the occupation lines while getting general topo information for the survey. I recall finding the shaft to a Hilti nail in the curb. It gave off enough of a magnetic signal for me to find the end of its shaft in a small depression in the curb formed when the nail had been blown into the curb. Snowplows can jump the curb and tear off the top of the nails and the washer but might still leave the shaft. I put the yellow crayon marks around it so I could find it later in the survey.

On a survey of a tract in a tall old forest, the deed called for a stone. Walking back to look for the stone, it seemed there was little hope of picking the needle out of the haystack of a forest. Then my eye caught an old wooden fence post, the type used for split rail fence. I stood behind the post, looked through the hole for the rail and used it as a sight for the possible property line. Through the woods, I spied another similar fence post and then projected that line ahead through the woods allowing me to come across fallen fence posts and eventually to the old stone monument. When I was within 10 feet, it was easy enough to see. But had I not used the occupation line formed by the ancient fence posts, I would not have found it that day. It will help you to stare into the woods looking for vertical lines of posts and horizontal lines of fences.

When I take a reading on an occupation line, I will code it “OL.” Since I do most of my own rough drafting, I know my codes and my employees will learn them too. Should they come up with some of their own, well, I like to have everyone draft up their fieldwork.

Getting back to the Cracker Jack land surveyor I worked for, he sent me to survey a large tract of land. This property was made up of what had formerly been called “Movie Theatre Lots.” Years ago, people attending the motion picture theatre would win a lot should their ticket be chosen as the winner. They would take a large tract of land, perhaps 50 acres or more, and on paper create lots using the deed description and 10 foot wide by 100 foot deep strips of land. If a person won a few, they could get them together and maybe buy some from another winner and put together enough land to build on. Because the tract boundary had not been surveyed accurately, or perhaps been a perch deed, there was a lot of error in the layout. Often the lots had no bearings.

When the boss sent me out to survey the tract, he educated me on “Movie Theatre Lots” and told me to locate what appeared to be the occupation lines of the houses within the large tract. He said that whatever I said was the boundary would be the boundary of the houses, which were here and there. He would create roads for those houses and then come up with a layout for the new lots on the total tract. Because he honored lines of occupation, everyone was satisfied when the pins for their lots were placed. I enjoyed the process and looking at what he had done.

These type of lots must exist all over the country and may have been created for many different reasons, but in the end, because the original lots were not properly surveyed, occupation lines held.

I was sent out on another survey nearby in which the lots were laid out on paper with distances to even feet but no bearings ever given. The head of surveys would review my locations of occupation lines and do the best he could under the circumstances. Roads were given their called for right of way widths, and the lot distances massaged in an effort to get close to the plan. When we were finished, the lot we surveyed would have bearings and distances and a recorded plan for the next surveyor to use.

This is the tip of the iceberg concerning ‘occupation lines.’ As surveyors, we are called upon to give our opinions of where our clients land exists and should always take notice of apparent ownership while in the field so the office staff is ready to back up their decisions on the final boundary lines.