# Relationship history for MSHA mine 3607847

Current hierarchy: **Northern Star Generation Services Co LLC → IP Harmar Holdings, LLC → Harmar  Refuse Site**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Market Coal Inc → Harmar  Refuse Site; 1986-11-01 to 1988-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Dennis N  Kostic → Harmar  Refuse Site; 1986-11-01 to 1988-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Dennis N  Kostic → Market Coal Inc; 1986-11-01 to 1988-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Minerals Technology Inc → Harmar  Refuse Site; 1988-04-01 to 2009-04-20; source msha-controller-operator-history
- **controller_controls_mine:** Inter-Power USA Inc → Harmar  Refuse Site; 1988-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Inter-Power USA Inc → Minerals Technology Inc; 1988-04-01 to 2009-04-20; source msha-controller-operator-history
- **operator_operates_mine:** IP Harmar Holdings, LLC → Harmar  Refuse Site; 2009-04-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Northern Star Generation Services Co LLC → Harmar  Refuse Site; 2009-04-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Northern Star Generation Services Co LLC → IP Harmar Holdings, LLC; 2009-04-21 to current/open; source msha-controller-operator-history