# Relationship history for MSHA mine 1510848

Current hierarchy: **Richard E  Salyer → Eldorado Coal Company Inc → 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

- **operator_operates_mine:** Eldorado Coal Company → No 1 Mine; 1977-10-01 to 1979-02-19; source msha-controller-operator-history
- **controller_controls_mine:** Stiltner Regis & Doug Viers → No 1 Mine; 1977-10-01 to 1979-02-19; source msha-controller-operator-history
- **controller_controls_operator:** Stiltner Regis & Doug Viers → Eldorado Coal Company; 1977-10-01 to 1979-02-19; source msha-controller-operator-history
- **operator_operates_mine:** Eldorado Coal Company Inc → No 1 Mine; 1979-02-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard E  Salyer et al → No 1 Mine; 1979-02-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard E  Salyer et al → Eldorado Coal Company Inc; 1979-02-20 to current/open; source msha-controller-operator-history