# Relationship history for MSHA mine 1515110

Current hierarchy: **Williams Robert → Birchfield Mining Company Inc → No 3 Site**

- 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:** Robin Roy Belcher → No 3 Site; 1980-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Williams Robert → No 3 Site; 1982-03-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** P B Dirt Movers Inc → No 3 Site; 1985-03-01 to 1987-07-14; source msha-controller-operator-history
- **controller_controls_operator:** Robin Roy Belcher → P B Dirt Movers Inc; 1985-03-01 to 1987-07-14; source msha-controller-operator-history
- **controller_controls_mine:** Wright Steve → No 3 Site; 1985-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Nighthawk Construction Company Inc → No 3 Site; 1987-07-15 to 1989-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Wright Steve → Nighthawk Construction Company Inc; 1987-07-15 to 1989-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Birchfield Mining Company Inc → No 3 Site; 1989-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williams Robert → Birchfield Mining Company Inc; 1989-08-01 to current/open; source msha-controller-operator-history