# Relationship history for MSHA mine 1512279

Current hierarchy: **Richard E  Salyer → Inferno Coals Inc → No 4**

- 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:** Sloan Curtis & David Belcher → No 4; 1975-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard E  Salyer et al → No 4; 1976-11-23 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Enduro Coal Company Inc → No 4; 1980-04-01 to 1981-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Sloan Curtis & David Belcher → Enduro Coal Company Inc; 1980-04-01 to 1981-09-14; source msha-controller-operator-history
- **operator_operates_mine:** Inferno Coals Inc → No 4; 1981-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard E  Salyer et al → Inferno Coals Inc; 1981-09-15 to current/open; source msha-controller-operator-history