# Relationship history for MSHA mine 0503960

Current hierarchy: **Redland Plc → Sterling Paving Company → Three Bell**

- 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

- **controller_controls_mine:** Koppers Company Inc → Three Bell; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sterling Paving Company → Three Bell; 1984-06-01 to 1987-04-20; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Sterling Paving Company; 1984-06-01 to 1987-04-20; source msha-controller-operator-history
- **controller_controls_mine:** Koppers Co Inc & Redland Plc → Three Bell; 1987-04-20 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sterling Paving Company → Three Bell; 1987-04-21 to 1988-06-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Co Inc & Redland Plc → Sterling Paving Company; 1987-04-21 to 1988-06-13; source msha-controller-operator-history
- **operator_operates_mine:** Sterling Paving Company → Three Bell; 1988-06-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Redland Plc → Three Bell; 1988-06-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Redland Plc → Sterling Paving Company; 1988-06-14 to current/open; source msha-controller-operator-history