# Relationship history for MSHA mine 1510842

Current hierarchy: **Bias C D → Eli Coal Company → No 1 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** 461 Coal Company → No 1 Surface; 1977-10-01 to 1977-12-27; source msha-controller-operator-history
- **controller_controls_mine:** Taylor Ralph W & Bill Hart → No 1 Surface; 1977-10-01 to 1977-12-27; source msha-controller-operator-history
- **controller_controls_operator:** Taylor Ralph W & Bill Hart → 461 Coal Company; 1977-10-01 to 1977-12-27; source msha-controller-operator-history
- **operator_operates_mine:** Eli Coal Company → No 1 Surface; 1977-12-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bias C D → No 1 Surface; 1977-12-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bias C D → Eli Coal Company; 1977-12-28 to current/open; source msha-controller-operator-history