# Relationship history for MSHA mine 1508921

Current hierarchy: **Ashland Inc → Addington Brothers Mining Inc → Flat Gap Surface**

- 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

- **controller_controls_mine:** Addington Larry & Robert → Flat Gap Surface; 1950-01-01 to 1976-10-31; source msha-controller-operator-history
- **operator_operates_mine:** Addington Brothers Mining Inc → Flat Gap Surface; 1975-09-23 to 1976-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Addington Larry & Robert → Addington Brothers Mining Inc; 1975-09-23 to 1976-10-31; source msha-controller-operator-history
- **operator_operates_mine:** Addington Brothers Mining Inc → Flat Gap Surface; 1976-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ashland Inc et al → Flat Gap Surface; 1976-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc et al → Addington Brothers Mining Inc; 1976-11-01 to current/open; source msha-controller-operator-history