When I began to work on Crosses of Iron, I knew there would be some aspects of the story that would require a lot of time to piece together.

The peak population of Dawson wasn’t one of them.Not only was I mistaken, but even now, with the book only months from its October release, I can’t say with absolute certainty how many people lived in Dawson during its glory days.

If you Google “Dawson New Mexico population,” you will find a range of numbers, the most popular being “around 9,000,” though you can find some reports as low as 3,000 and as high as 10,000. The problem with these numbers is that they are not attributed to a specific source.

Here’s what I know about Dawson’s population, at least based on official U.S. Census data:

— 1900: 100
— 1910: 3,119
— 1920: 4,045
— 1930: 2,698
— 1940: 1,613
— 1950: 1,200

I also know that Dawson’s mine employment peaked in 1915 (1,640 workers), according to Phelps, Dodge & Co. records, which would be in line with census data that shows the population rising between 1910 and 1920. But did it continue to grow — and, if so, by how much — during the 1920s before falling below 3,000 at the end of the decade?

For the book, I chose to go with “roughly 6,000,” a number consistent with population figures cited in The Dawson News, the Phelps Dodge-run newspaper published between 1921 and 1929.

When the weekly newspaper debuted on Feb. 3, 1921, the editor described Dawson as “a community of over 5,000 people.” Three years later, in a News pictorial supplement published on May 1, 1924, the population was listed as 6,000, “the largest town in the Southwest supported by a single industry.”

While it’s possible the number of residents ticked up over the next few years, that seems unlikely given that mine employment fell by more than half over the rest of the decade.

Six thousand is also the number that appears on the official scenic historic marker for Dawson.

Still, if anyone knows the origin of the 9,000 figure, I’d love to know.