Historical early mapping: Township and Range

We are now used to GPS tools to mark locations with accuracy using precise latitude and longitude units or Universal Transverse Mercator (UTM) measurements, but for more than 100 years, the western U.S. used a rectangular surveying system that seems complicated but was very effective.

In 1785, the U.S. decided that the western territories would be surveyed by a rectangular system that consisted of six-mile square boxes called townships that each included 36 sections of one square mile, containing 640 acres each. Texas would maintain a separate system. To survey the land, two men would carry a 66-ft long chain, and 80 chains would correspond to 1 mile (5,280 feet).

Townships are numbered either north or south of an east-west central dividing line, while ranges are numbered east or west of a central north-south dividing line. To completely describe a location, you would use both the township and range (e.g. township T1N R3W for Township 1 North and Range 3 West), then the specific section, then further describe subdivisions within that section.

Note the unconventional way of numbering the 36 sections. Numbering in this pattern ensures that numerically sequential sections within the same township are physically adjacent and share colinear boundaries.

In 1854, the point of origin for the rectangular grid in New Mexico was selected as a small hill east of San Acacia, 12 miles north of Socorro. A north-south line called the New Mexico Principal Meridian, then an east-west Base Line was surveyed.

New Mexicouses this Public Land Survey System (PLSS) but has several areas that retain original metes and bounds from Spanish and Mexican rule. These take the form of land grants similar to areas of Texas and California.

Sections, half sections, and quarter sections would eventually also define the farming areas. The Homestead Act of 1862 allowed up to a quarter of a section (160 acres) to be acquired by a head of household. Note that this amount of land in the arid west would only support about 10 heads of cattle, not enough to support a family.

In 1878, J. Wesley Powell, the second director of the USGS of Grand Canyon expedition fame, wanted to abandon in the arid region the prevailing method of laying out political and land subdivisions by the township, range, and section method.

Powell was against the township/range system because the prevailing grid-based method allowed settlers to acquire parcels of land without consideration of water. Parcels could include streams within the parcel, without obligation to permit settlers on any of the adjacent farms to have access to the water.

Disputes arising from those circumstances seemed inevitable, and if the adjoining farms should happen to lie in another township or in another county, any settlement thereof could become increasingly difficult. Powell tried to direct surveys of the arid western U.S. under irrigation principles, but he eventually failed to convince congress and resigned.

The township system was also used for more than 100 years to locate oil and gas wells and groundwater wells. Each section can be divided into successive quarters.

For example, a groundwater well in Los Lunas can be designated, based on one of the meridians, as Well 7N. 2W. 28. 234 (Meridian Label) to describe its location in Section 28 of the Township 7 North, Range 2 West (Figure 1). The last three digits designate the corresponding 10-acre portion of Section 28. Within the 640-acre section, the well is in its second 160-acre quarter, in the third 40-acre quarter of that quarter, and in the fourth 10-acre quarter of that quarter.

Of course, because the earth is not flat, and the north-south edges west and east of each township are actually angled towards each other since the lines are all aimed to a convergence pole in the north, this requires occasional survey adjustments to maintain the square mile systematic unit. The adjustments are made in the 11 northernmost and westernmost sections, leaving the other 25 sections intact as one square mile.

Also, under the 1785 Act and following acts, the federal government granted to the Territory of New Mexico sections 2, 16, 32, and 36 in every 36-square mile township to be used for education. Where those lands belonged to a tribe or other owner, New Mexico was allowed to pick lands elsewhere. These are today managed by the State Land Office, which maximizes revenues from these lands to provide funds for education and the environment.

In addition, sections were awarded to the railroad building companies through the Pacific Railroad Act of 1862 (signed by President Abraham Lincoln). That act was the first major land grant specifically for the transcontinental railroad and provided public lands for a railroad right-of-way to build rail systems. In addition to the 400-foot wide right of way for the railroad itself, millions of acres were awarded to raise the capital needed to build and maintain the future railways.

Ten square miles of land on each side of the proposed rail track were granted for every one mile of completed railway. The land was granted in alternating one-square-mile sections, with each odd numbered section going to the railroad company and each even numbered section kept by the government. This created a checkerboard pattern along proposed railways. This was supposed to guarantee that railroad access would increase the value of bot h the railroad-granted sections and the government-owned sections in the checkerboard.

A review of maps prepared by the Bureau of Land Management shows the township and range grids, the non-surveyed original Land Grant areas, and the checkerboard pattern of square miles that illustrates the private parcels and the parcels reserved for state controls.

(Paul Parmentier, a certified professional geologist retired from California and living in Los Lunas, shares the rich geologic features in Valencia County. He earned a Bachelor of Science degree in geology from Belgium and a master’s degree in geochemistry from Japan. The Geologic Landscapes and Observations of Surrounding Nature of Valencia County are featured monthly.)