# Relationship history for MSHA mine 3303257

Current hierarchy: **Lafarge Coppee → Standard Lafarge → Wheelersburg 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

- **controller_controls_mine:** Belville Thomas & Robert → Wheelersburg Dock; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bellville Mining Company Inc → Wheelersburg Dock; 1974-12-01 to 1977-03-21; source msha-controller-operator-history
- **controller_controls_operator:** Belville Thomas & Robert → Bellville Mining Company Inc; 1974-12-01 to 1977-03-21; source msha-controller-operator-history
- **operator_operates_mine:** Standard Materials Inc → Wheelersburg Dock; 1977-03-22 to 1994-05-23; source msha-controller-operator-history
- **controller_controls_mine:** Standard Slag Company → Wheelersburg Dock; 1977-03-22 to 1994-05-23; source msha-controller-operator-history
- **controller_controls_operator:** Standard Slag Company → Standard Materials Inc; 1977-03-22 to 1994-05-23; source msha-controller-operator-history
- **operator_operates_mine:** Standard Lafarge → Wheelersburg Dock; 1994-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge Coppee → Wheelersburg Dock; 1994-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge Coppee → Standard Lafarge; 1994-05-24 to current/open; source msha-controller-operator-history