# Relationship history for MSHA mine 3303998

Current hierarchy: **Pittston Company → Ironton Coal Company → Ironton River Dock**

- 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:** Ironton Coal Company → Ironton River Dock; 1984-11-01 to 1994-01-13; source msha-controller-operator-history
- **controller_controls_mine:** Horizon Natural Resources Incorporated → Ironton River Dock; 1984-11-01 to 1994-01-13; source msha-controller-operator-history
- **controller_controls_operator:** Horizon Natural Resources Incorporated → Ironton Coal Company; 1984-11-01 to 1994-01-13; source msha-controller-operator-history
- **operator_operates_mine:** Ironton Coal Company → Ironton River Dock; 1994-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pittston Company → Ironton River Dock; 1994-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pittston Company → Ironton Coal Company; 1994-01-14 to current/open; source msha-controller-operator-history