# Relationship history for MSHA mine 3401755

Current hierarchy: **Reeves Phillip G → Oklahoma Coal Development Inc → Blake Mine 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Cypress Grove Coal Company → Blake Mine No 1; 1991-05-01 to 1994-03-09; source msha-controller-operator-history
- **controller_controls_mine:** Roger E  Dahlgren → Blake Mine No 1; 1991-05-01 to 1994-03-09; source msha-controller-operator-history
- **controller_controls_operator:** Roger E  Dahlgren → Cypress Grove Coal Company; 1991-05-01 to 1994-03-09; source msha-controller-operator-history
- **operator_operates_mine:** Oklahoma Coal Development Inc → Blake Mine No 1; 1994-03-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Reeves Phillip G → Blake Mine No 1; 1994-03-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Reeves Phillip G → Oklahoma Coal Development Inc; 1994-03-10 to current/open; source msha-controller-operator-history