The drawing of Arizona’s counties

By Tom Prezelski

Geographers will tell you that a straight line on a map is the legacy of a political decision made by people far away who were unaware of the conditions on the ground. County boundaries in Arizona are a particular demonstration of this rule. In the earliest days of the territory, much of Arizona was unsurveyed, and some parts, particularly in the north, were still unexplored. As a result, the lines were largely demarcated out of convenience. This has led to occasional problems.

Arizona established its first counties in 1864: Mohave, with the county seat at Mohave City; Pima, with the county seat at Tucson; Yavapai with the county seat at Prescott; and Yuma, with the county seat at La Paz. The legislature could not create more counties if they wanted to, as there were almost no other civilian settlements substantial enough to pass for towns that could serve as county seats. The territory was so sparsely settled that any more would have been impractical and unnecessary.

As new settlements developed, the legislature would create new counties by dividing the old ones. Typically, this happened when a new town or mining camp grew large enough to influence elections and create enough political pressure to drive legislation. The wild west boom and bust economy meant that such things could move quickly.

The first change to Pima County’s boundaries occurred in 1873. Two years before, the growth of communities like Phoenix and Hayden’s Ferry on the Salt River led to the formation of Maricopa County out of a piece of Yavapai. It was not long before settlers along the south bank of the lower Gila River agitated to be annexed to the new county, Phoenix being more convenient to them than Tucson. The legislature responded by expanding Maricopa County to include the area, thus setting the precedent of Maricopa taking from Pima.

Pinal County was formed in 1875 to accommodate the growth of Florence. Pinal likewise took a large chunk of Pima County. The legislation was so poorly written that it left a small piece of Pima County as an island surrounded by Maricopa and Pinal. It was up to the next legislature in 1877 to fix this by handing the orphan land over to Pinal.

The mining camp of Tombstone was established after silver was discovered in a remote part of Pima County in 1879. By 1881, the town was so large that representatives from there dominated Pima County’s delegation to the legislature. Though Tombstonites had a good case for why they deserved their own government, officials in Tucson feared the loss of property taxes. In the end, Tucson lost the argument, and the legislature cut Pima County to create Cochise. What remained to the north became part of the new county of Graham, which was probably not yet developed enough to justify self-governance, and remained dysfunctional for years.

The last major change to Pima’s boundaries came in 1899, when civic boosters from the growing border town of Nogales and cattlemen from the Sonoita and San Rafael Valleys successfully lobbied for the creation of Santa Cruz County.

Decades later, a problem of a badly drawn line led to one of the most pointless land disputes in Arizona’s history, though in fairness, the question would have to be settled eventually.

Legislation in 1873 and 1877 defined Pima County’s northern boundary as the “second parallel south,” a reference to the rectangular survey system of townships and ranges used to allocate land in the 19th century which is still used to define most property today. Because of the way that Arizona was settled, surveys of available public land were conducted piecemeal as they became necessary. The result is that the gridlines are sometimes mismatched due to errors by surveyors or the use of different standards by different workers in the field.

By the 1920s, folks had noticed that, as a product of such inconsistencies, the northern boundary of Pima County was irregular. In 1923, Maricopa County sued Pima, claiming jurisdiction over some 600 square miles of undeveloped desert along the line north of Ajo. The area lacked mineral wealth or agricultural potential, so it was never going to be taxable property. Maricopa County simply wanted to increase its land base for statistical purposes. The resulting court battle lasted five years, until, in a ruling that cited the 1877 legislation, the State Supreme Court found for Maricopa County for a reduced amount of 360 square miles.

The line remains jagged in a few places, notably one location at the north-east corner of Marana where there is a jog of nearly two-thirds of a mile. This is the legacy of a convergence of political expedience and inadequate knowledge of what was actually on the ground. This sort of error is hardly unique in Arizona, and given the haste with which counties were drawn, it is a wonder that disputes do not occur more often.


Tom Prezelski. Prezelski is a Tucson native and former member of the Arizona House of Representatives. His first book, Californio Lancers: The 1st Battalion of Native Cavalry in the Far West was a finalist for the 2016 Latino Book Awards.



Click here for reuse options!
Copyright 2017 Southern Arizona News-Examiner