Here are Butler County’s top employers, with the community where they operate and the number of full- and part-time employees.

1. Iron Mountain Underground Storage, Boyers — 1,852, employed by about 11 businesses within the facility, including U.S. Investigations Services with 973 employees
2. Butler Health System, including Butler Memorial Hospital, Butler — 1,647
3. AK Steel, Butler Township — 1,600
4. Butler School District, Butler and Butler Township — 1,198
5. Traco, Cranberry Township — 1,200
6. Butler County Community College, campuses in Cranberry and Butler townships — 1,178
7. Wal-Mart, Cranberry and Butler townships and Sam’s Club in Butler Township — 1,070
8. Giant Eagle, stores throughout county and its subsidiary Butler Refrigerated Meats in Lancaster Township — 953
9. Verizon Wireless, Cranberry Township — 925
10. Seneca Valley School District, Jackson Township — 900
11. Concordia Lutheran Home, Jefferson Township — 880
12. Slippery Rock University, Slippery Rock — 876
13. Butler County Government, Butler — 856
14. Lutheran Senior Life, Mars, Zelienople and Cranberry Township — 750
15. Penn United Technologies, Jefferson Township — 712
16. Mine Safety Appliances, Cranberry Township — 679
17. Butler Auto Auction, Cranberry Township — 670
18. Armstrong, Butler — 676
19. II-VI Inc., Clinton Township — 540
20. Butler Veterans Affairs Medical Center, Butler Township — 508