# Relationship history for MSHA mine 4607485

Current hierarchy: **David  Stevenson → Conquest Coal Mining Inc → 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Endicott Shelby R → Mine No 1; 1987-01-07 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ro-Ann Mining Inc → Mine No 1; 1988-03-01 to 1988-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Endicott Shelby R → Ro-Ann Mining Inc; 1988-03-01 to 1988-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Blazer Mining Inc → Mine No 1; 1988-09-01 to 1988-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Bunn Edward → Mine No 1; 1988-09-01 to 1988-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Bunn Edward → Blazer Mining Inc; 1988-09-01 to 1988-09-14; source msha-controller-operator-history
- **operator_operates_mine:** Conquest Coal Mining Inc → Mine No 1; 1988-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David  Stevenson → Mine No 1; 1988-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Stevenson → Conquest Coal Mining Inc; 1988-09-15 to current/open; source msha-controller-operator-history