At the time, the brand new county was home to about 4 percent of the state's population and little of its wealth. Only a few hundred people lived in and around the new county seat, but many of them turned out to mark that historic day.

The July 3, 1909, edition of the Las Vegas Age recounted the "general rejoicing."

At the stroke of midnight on July 1, Clark County's birth was greeted "with the ringing of bells and other noises too numerous to mention."

"Flags were hoisted to the breeze and congratulations exchanged at the realization of the hopes of many months."

With the account, the newspaper published a map of the new county. Many of the towns and mining camps pictured there -- places like St. Thomas, Rioville, Manvel and Owens -- would not survive to see the centennial.

More than anything else, the decision to divide Lincoln County came down to convenience, said Mark Hall-Patton, museum administrator for present-day Clark County.

Residents with business to conduct in the Lincoln County seat of Pioche had to travel more than 125 miles from Las Vegas and more than 200 miles from the southernmost tip of the state.

"It was very difficult to get there. It was a couple days' ride," Hall-Patton said. "You can imagine the trip up from Searchlight."

But before the split was allowed to go forward, Lincoln County officials demanded assurances that the new county would share in the cost of a new courthouse in Pioche.

Hall-Patton said Clark County agreed to cover 60 percent of the price tag for a building it would never use. Massive cost overruns earned the structure a nickname: the million-dollar courthouse. The debt on the building wasn't paid off until the early 1930s, four years after the courthouse was condemned, Hall-Patton said.

Clark County was named for William Andrews Clark, a mining and railroad magnate who gave Las Vegas its start when he established a maintenance stop for his San Pedro, Los Angeles & Salt Lake Railroad.

Another Clark also played a key role, Hall-Patton said. Pioche businessman Edward Clark worked behind the scenes to make the county split possible. His reward was an appointment as Clark County's first treasurer.

The new county's population, counted officially for the first time during the 1910 census, stood at 3,321 souls.

That's about 600 more than the current enrollment at Clark High School and 27 fewer than the number of guest rooms at Caesars Palace.

Hall-Patton said Clark County's two largest communities a century ago were Searchlight and Goodsprings, and its two largest employers were mines and ranches.

The county was transformed in the decades that followed, first by the railroad, then by Hoover Dam, the war effort, the quickie divorce and the rise of the Strip. More than 2 million people now call Clark County home, nearly 72 percent of the state's population.

In some ways, though, the county hasn't changed all that much, Hall-Patton said.

"Water was an issue then, and water is an issue now," he said. "We've gone from railroads to aircraft," but transportation is still a crucial piece of the local economy.

"There's still similarities," Hall-Patton said.

Similarities and one constant: 100 years of more booms than busts.

Contact reporter Henry Brean at hbrean@reviewjournal.com or 702-383-0350.