# Relationship history for MSHA mine 1516709

Current hierarchy: **Richard E  Salyer → Eldorado Coal Company Inc → Collins Mine No D-3**

- 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:** Richard E  Salyer et al → Collins Mine No D-3; 1979-02-20 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Eldorado Coal Company Inc → Collins Mine No D-3; 1989-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard E  Salyer et al → Eldorado Coal Company Inc; 1989-09-01 to current/open; source msha-controller-operator-history