# Relationship history for MSHA mine 1516320

Current hierarchy: **Donn A  Chickering → Branham & Baker Coal Company Inc → Inferno #6**

- 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:** Donn A  Chickering → Inferno #6; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard E  Salyer et al → Inferno #6; 1976-11-23 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Inferno Coals Inc → Inferno #6; 1988-03-01 to 1989-01-29; source msha-controller-operator-history
- **controller_controls_operator:** Richard E  Salyer et al → Inferno Coals Inc; 1988-03-01 to 1989-01-29; source msha-controller-operator-history
- **operator_operates_mine:** Branham & Baker Coal Company Inc → Inferno #6; 1989-01-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donn A  Chickering → Branham & Baker Coal Company Inc; 1989-01-30 to current/open; source msha-controller-operator-history