# Relationship history for MSHA mine 4002650

Current hierarchy: **Walt Fred → Roane County Rock Inc → Walt Quarry**

- 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:** Roane County Rock Inc → Walt Quarry; 1980-09-01 to 1984-12-17; source msha-controller-operator-history
- **controller_controls_mine:** Webster Steve → Walt Quarry; 1980-09-01 to 1984-12-17; source msha-controller-operator-history
- **controller_controls_operator:** Webster Steve → Roane County Rock Inc; 1980-09-01 to 1984-12-17; source msha-controller-operator-history
- **operator_operates_mine:** Roane County Rock Inc → Walt Quarry; 1984-12-18 to 1986-09-24; source msha-controller-operator-history
- **controller_controls_mine:** Jenkins Ralph → Walt Quarry; 1984-12-18 to 1986-09-24; source msha-controller-operator-history
- **controller_controls_operator:** Jenkins Ralph → Roane County Rock Inc; 1984-12-18 to 1986-09-24; source msha-controller-operator-history
- **operator_operates_mine:** Roane County Rock Inc → Walt Quarry; 1986-09-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Walt Fred → Walt Quarry; 1986-09-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walt Fred → Roane County Rock Inc; 1986-09-25 to current/open; source msha-controller-operator-history