Originally housing inmates[1] from the 14 northwestern Pennsylvania counties.

In 1986, the facility also accepted inmates from the southwestern 9-county region that were utilizing SCI-Greensburg.

Presently, inmates from all over the commonwealth are housed at SCI Mercer.

There are 30 buildings on SRCF Mercer's Campus (23 inside the 37.5 acre fenced perimeter).

The institution operates its own sewage treatment plant, having a 104,000 gallon daily capacity.