Eastern Oregon is building quite the reputation as the home of the West Coast data center, and Facebook added to that legacy Tuesday with plans to build two new data centers at its existing campus in Prineville by 2021.

Facebook already operates three data centers in Prineville that surface those embarrassing pictures from last year’s company holiday party, and before the year is out it will break ground on a fourth one, it said in a blog post Tuesday. Construction of a fifth data center will start next year, said KC Timmons, data center operations for Facebook, in the post.

Apple has also constructed a data center complex in Prineville, and Google has its own collection of data centers in The Dalles, a little over two hours north of Prineville on the Columbia River. Amazon Web Services operates at least eight data centers in the region, and was reportedly seeking to open a ninth earlier this year.

Why Eastern Oregon? While it is certainly a lovely place (if you like wide open spaces), the region enjoys easy access to cheap hydropower thanks to the dams along the Columbia River dividing Oregon and Washington. Oregon is also the landing point for new undersea cables traveling under the Pacific, and as cloud computing starts to run into latency issues, having data centers as close to those high-speed cables as possible helps things along.

And, of course, there’s another reason: job-hungry counties in Eastern Oregon have doled out millions in tax breaks to companies that set up shop in the region. As noted by The Oregonian, Facebook has received $71.6 million in tax considerations from local governments since 2012.

But while data centers certainly create a lot of construction jobs, they employ a surprisingly small number of people on a regular basis. Facebook’s three current data centers, which cover 1.25 million square feet, require just 200 people to operate, the company said.