# Relationship history for MSHA mine 1517089

Current hierarchy: **Carver Bobby → Oak Ridge Coal Company Inc → No 1**

- 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:** Silver Bullet Mining Inc → No 1; 1991-06-01 to 1992-12-21; source msha-controller-operator-history
- **controller_controls_mine:** Kennith  Layne et al → No 1; 1991-06-01 to 1992-12-21; source msha-controller-operator-history
- **controller_controls_operator:** Kennith  Layne et al → Silver Bullet Mining Inc; 1991-06-01 to 1992-12-21; source msha-controller-operator-history
- **operator_operates_mine:** Oak Ridge Coal Company Inc → No 1; 1992-12-22 to 1993-03-21; source msha-controller-operator-history
- **controller_controls_mine:** Estep Paul → No 1; 1992-12-22 to 1993-03-21; source msha-controller-operator-history
- **controller_controls_operator:** Estep Paul → Oak Ridge Coal Company Inc; 1992-12-22 to 1993-03-21; source msha-controller-operator-history
- **operator_operates_mine:** Oak Ridge Coal Company Inc → No 1; 1993-03-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Carver Bobby → No 1; 1993-03-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carver Bobby → Oak Ridge Coal Company Inc; 1993-03-22 to current/open; source msha-controller-operator-history