When Bench Marks & Section Corners Collide

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Prior to the 1896-97 field season, surveyors with the U. S. Geological Survey, who were engaged in the topographic mapping of the United States, left very few bench marks for public use. USGS came under scrutiny for failing to establish permanent monuments and many claimed the work was useless to the public without them. Surveyors and engineers using the new topographic maps could see the accurately plotted contours and elevations, but had no way to replicate or place these features on the ground without having permanent markers from which to start.

After years of discussion, the Act of Congress providing for the Sundry Civil Expenses of the Government for the fiscal year 1896-97, included among the items of appropriation, available funds to USGS for the procurement of permanent monuments. From that time forward, all new surveys would leave permanent bench marks as a requirement with the field work. At least two bench marks were to be established in each township or equivalent area except in forest or mountain areas where at least one would be placed. The majority of this work began west of the 95th Meridian. The suggested locations were for the bench marks to be placed near the township corners of the public land surveys, if possible, so they could be more easily found.

This action was seen as a remedy to a known defect in the government’s work and would be of great benefit to the public. The placement of these permanent bench marks, however, later caused confusion when many of the surveyors of USGS doing the leveling work took the instructions to place the bench marks `near’ the township corners too literally. Heavy wrought-iron posts 3 ½ inches in diameter with bronze caps began appearing within a few feet of township or other section corners that had been previously established by the General Land Office. The monuments established by the GLO for section corners were usually inferior monuments such as stones or wooden stakes in mounds. One notable exception was for certain township corners established by USGS in Indian Territory (Oklahoma) where the new iron bench mark monuments were placed for the township corners.

Prior to the 1902 Manual of Instructions, the GLO had not suggested the use of iron monuments for section corners. As the stones, stakes, or earth mounds marking the section corners gradually were obliterated by forces of nature, the iron bench marks placed near them by USGS generally remained as a beacon to the unwary surveyor who came to the location in search of the section corner. While some USGS surveyors noted the exact distance and direction to the section corner from the bench mark at the time of placement, others merely stated they were placed `at the corner’ giving the impression that the bench mark and the section corner positions were one and the same. This verbiage was often a generalization and was only intended to bring the surveyor to the approximate area where the situation should then be obvious. A section corner at a road intersection was generally in the road while the bench mark was placed off to the side in a nearby fence line. The bench mark in this case might be more than fifty feet away, but the published description implied it was at the section corner. In areas where roads did not exist, the usual procedure was to place the bench mark very close to the section corner.

To further complicate matters, the General Land Office later began using the same manufacturer to produce iron monuments for section corners that USGS had used for their bench marks. Monuments established at township corners were nearly identical in size and appearance except for the embossing on the caps. Surveyors who were unfamiliar with the existence of these early bench marks, or who did not take the time to read the wording on the caps, invariably mistook them for section corners.

One notable area of confusion was the Sandhills region in the central and western portions of Nebraska where the original GLO surveys were performed in the 1870’s by leaving pits and mounds for corner monuments. In the late 1890’s, USGS established many iron bench marks in this same region, placing some at the township corners which were nearly obliterated. Resurveys by the GLO in the 1910’s, found the remains of the original pits and mound corners and remonumented them with iron pipes with bronze caps. Sometimes the USGS bench mark would be only a few feet away.

At the township corner common to T17-18N, R40-41W, 6PM, a capped iron post bench mark was placed in 1898 next to the stake in mound that was established in 1875. In 1910, the GLO found evidence of the original pits and remonumented the township corner by setting a capped iron pipe of the same diameter as the bench mark, recording the distance and direction of 3 links (1.98 feet) between the two monuments. In the ensuing years, an unknown party moved the township corner to line up with the fence, but the recorded distance and direction to the bench mark, along with other evidence allowed the township corner to be correctly reset at its true location.

In the Black Hills of South Dakota, a USGS capped iron post bench mark was placed 2.3 feet north of the township corner common to T5-6N, R1-2E, BHM, which at that time was a 4-inch square pine post established in 1878. During a resurvey of the township lines in 1930, the bench mark was either moved or incorrectly thought to be the township corner since today it is stamped with markings indicating it to be the township corner. At another location, a USGS bench mark was placed 5.25 feet from the stone section corner, but today a pipe with aluminum cap by the Department of Agriculture, placed in 1982, is 4.30 feet from the bench mark.

The full extent of placing bench marks next to section corners is not fully known, but it probably occurred in various places all across the western United States. In some instances, as previously described, the bench marks have acted as a witness to the section corner position when the distance between them was previously known, but in other cases they have evolved into being the corner position when proper research was not done. It is imperative that the surveyor gain a clear understanding through proper research as to what the agency did in each area surveyed to correctly know what a particular monument represents.

Jerry Penry is a licensed land surveyor in Nebraska and South Dakota. He is a frequent contributor to the magazine.

A 5.114Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

About the Author

Jerry Penry, PS

Jerry Penry has been surveying for 34 years, is licensed in Nebraska and South Dakota, and has been employed with Lancaster County Engineering for 21 years. He is also serving his second term on the Board for the Professional Surveyors Association of Nebraska.