LAS VEGAS - It is an anniversary every bit as historic as Nevada Day or the city's centennial, but no one will get the day off.
There will be no parade downtown, no birthday cake the size of a basketball court. Thursday will pass just like any other day in Las Vegas, even if it isn't.
On Jan. 18, 1867 - 140 years ago this month - the newly minted Silver State launched its third year of statehood by taking possession of a mostly empty, triangle-shaped slice of the Arizona Territory, just west of the Colorado River.
The acquisition took in all of present-day Nevada south of 37 degrees latitude, including all of Clark County, which today is home to more than 70 percent of Nevada's population and roughly an equal share of its economic output.
"No one could have foreseen the outcome that we have now," State Archivist Guy Rocha said. "This state has tilted to the south and not the north."
The story doesn't end there.
Due to an oversight by officials in Carson City at the time of the acquisition, Nevada's Constitution was never amended to reflect the addition of the state's southern tip. The discrepancy would remain on the books for the next 115 years.
"The action that needed to be taken was taken by the Legislature and the governor (in 1867). What they failed to do was the follow-up," said Rocha, who researched the boundary intrigue and wrote an essay about it last year as part of his "Historical Myth a Month" series.
To some, it was a mere bookkeeping error. To others, including two men locked up for murder, it provided legal weight to an argument as old as Nevada itself: that Clark County - and Las Vegas in particular - really belongs to some other state.
Prison inmate Jerome Peter Kuk was the first to raise the issue in court. In 1968, he challenged his murder conviction on the grounds that Clark County wasn't actually in Nevada so prosecutors lacked the jurisdiction to try him under state law.
Convicted murderer Antonio Surianello tried a similar tactic in 1976.
The Nevada Supreme Court ultimately rejected both arguments.
"It certainly consumed a lot of people's time, let's put it that way," Rocha said. "A tremendous amount of time and energy and money was spent because some people in 1867 didn't do their jobs. What they left us with was a history of unfinished business."
Former Nevada Legislative Counsel Frank Daykin, 85, recalls the effort he led 25 years ago to clear up the mess once and for all, a feat finally accomplished through legislative decree and a statewide ballot measure.
Though some rural representatives were still stinging from a reapportionment that delivered more seats to Clark County, the constitutional amendment met no serious opposition from lawmakers.
"It was pretty much treated as a housekeeping measure," Daykin said.
"There were a few legislators who, in moments of frustration, might have wanted things to stay the way they were," he said with a chuckle. "Jim Slattery, the senator from Storey County, God rest his soul, kind of wished they would have cut (Southern Nevada) off."
Ultimately, the amendment passed the Legislature in 1981, and Nevada voters approved it by an almost 2-1 margin in November 1982.
The measure passed in every county, though the margin was wider in some places than others. Mineral County came within 116 votes of rejecting the idea of adding Southern Nevada to the state's constitutional boundaries.
Norma Scott, who has called Hawthorne home since 1939, remembers the ballot measure well.
She voted against it, and she encouraged everyone she knew to do the same.
Scott said the rural county had just lost an Assembly seat to reapportionment, and many people were worried about the growing political clout of Las Vegas.
"They were trying to run the whole state," Scott said of Clark County residents. "My thought was, 'Let Arizona have them. We'll be better off without them.'"
Apparently, the feeling was mutual. Of the 76,514 ballots cast against including Southern Nevada in the constitutional description of the state, almost 60 percent came from Clark County voters.
Scott said she has made peace with the boundary change in the 25 years since the vote.
But she still thinks "those of us in rural Nevada struggle to get our fair share."
"It's done with, so we just accept it and go on," she said, only half-kidding.
But like it or not, Rocha said, Jan. 18 is an anniversary that deserves to be observed by residents on both sides of 37th parallel.
After all, the addition of Southern Nevada forever changed the state's destiny.
"It was quite a coup for Nevada to have access to the Colorado River. We came to know how important that was in the early 20th century," Rocha said.
It started with construction of Hoover Dam, which brought workers and industry to the area.
Then came the casinos.
"By 1967, with the growth of the Strip, Las Vegas had eclipsed Reno as a gambling tourist destination," Rocha said.
Ready access to the river made all of that possible.
It continues to fuel growth in the Las Vegas Valley, where about 90 percent of the drinking water comes from the Colorado.
"That's what rounded out Nevada," Rocha said of the land acquisition. "In the end, it's Nevada's gain and Arizona's loss."