# Relationship history for MSHA mine 1506859

Current hierarchy: **Williams Companies Inc → Mc Coy Elkhorn Coal Corp → No 1 Tipple (D)**

- 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:** General Energy Corp → No 1 Tipple (D); 1950-01-01 to 1982-04-29; source msha-controller-operator-history
- **operator_operates_mine:** Mc Coy Elkhorn Coal Corp → No 1 Tipple (D); 1973-01-01 to 1982-04-29; source msha-controller-operator-history
- **controller_controls_operator:** General Energy Corp → Mc Coy Elkhorn Coal Corp; 1973-01-01 to 1982-04-29; source msha-controller-operator-history
- **controller_controls_mine:** Williams Companies Inc → No 1 Tipple (D); 1982-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mc Coy Elkhorn Coal Corp → No 1 Tipple (D); 1982-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williams Companies Inc → Mc Coy Elkhorn Coal Corp; 1982-04-30 to current/open; source msha-controller-operator-history