# Relationship history for MSHA mine 1512702

Current hierarchy: **Dawson Fred → English Elkhorn → No 1 Mine**

- 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:** Webb George D → No 1 Mine; 1980-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Howes Clayton → No 1 Mine; 1980-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sawgrass Coal Company Inc → No 1 Mine; 1981-01-01 to 1981-04-22; source msha-controller-operator-history
- **controller_controls_operator:** Webb George D → Sawgrass Coal Company Inc; 1981-01-01 to 1981-04-22; source msha-controller-operator-history
- **operator_operates_mine:** Howes Coal Company Inc → No 1 Mine; 1981-04-23 to 1982-03-07; source msha-controller-operator-history
- **controller_controls_operator:** Howes Clayton → Howes Coal Company Inc; 1981-04-23 to 1982-03-07; source msha-controller-operator-history
- **operator_operates_mine:** English Elkhorn → No 1 Mine; 1982-03-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dawson Fred → No 1 Mine; 1982-03-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dawson Fred → English Elkhorn; 1982-03-08 to current/open; source msha-controller-operator-history