I just found out (thanks Jen!) that eBird shows how many checklists have been submitted in each county in Oregon. As people tend to do more of their birding closer to home, I'd have expected that the number of checklists submitted would roughly parallel the population of the county.
But that would be wrong.
The most obvious outlier is Benton County. Its population of 89,000 is the 11th most populous county (Multnomah with 800,000 is first), but Benton has had 86,000 checklists while Multnomah is 3rd with 63,000 (Lane is 2nd).
So how does Benton with about 1/9th the population of Multnomah (and 1/4th the population of Lane) get so many checklists submitted? Is every student at OSU required to eBird?