One year after Minneapolis hit 400,000, and just as St. Paul is reaching 300,000, Washington County is just a tick or two away from hitting a major population milestone of its own: a quarter of a million.
With an estimated 2014 head count of 249,109, and an average annual growth rate of 2,750 people so far this decade, the county almost certainly has hit the mark already.
It's a moment to glance back at more than a century and a half of growth, decline and boom times, phase by phase. So here's a quick narrative version of the squiggles you see on the chart on this page.
1850-1914: Boom No. 1
Viewed from the heights of 250,000, the county's early growth looks downright glacial. It took a full century to add as many people as would later flood in during a pair of decades.
"The early years were boom times for the county," said Brent Peterson, director of the Washington County Historical Society. "A huge percentage of all those living in the entire state were right here in Washington County."
Indeed: Nearly 1 in 5 people as of 1850, though that figure would shrivel to the 1 percent to 4 percent range over time.
On Aug. 24, 1839, in Marine on St. Croix, the Marine Lumber Company "cut its first pine log and became the first commercial sawmill in what was to become the State of Minnesota," reports the Minnesota Historical Society, which owns the site's ruins today.
Soon steam-powered sawmills all along the St. Croix River were sending valuable lumber elsewhere, and farmers profited from feeding the logging teams. Population quintupled in the 1850s, doubled again in the 1860s, then grew at slower rates until it went into decline.