Arizona has 15 counties today. That's not the fewest among U.S. states (Delaware has only three counties), but it isn't many — especially given the size of our state. In fact, 13 of the 15 counties rank among the 100 largest counties in America, and Coconino County is the country's second-largest, behind only San Bernardino County in California.

So it's hard to imagine that long ago, before Arizona became a state, the Arizona Territory had just four counties. And in the 1860s, a fifth county came along — and became an odd footnote in Arizona history.

Mohave, Yuma, Pima and Yavapai were the original four counties, created in 1864. A year later, the Territorial government split Mohave County in half to create Pah-Ute County. The new county, in the northwest corner of the state, included much of present-day Clark County, Nevada, including the site that one day would become Las Vegas.

But the new county was short-lived. In 1867, Congress expanded the state of Nevada to include land west of the Colorado River, including part of Pah-Ute County. When that happened, there was no reason for Pah-Ute to exist, and shortly thereafter, it was merged back into Mohave County.

Do you know any other odd facts about Arizona's history? Let us know in the comments!