# Relationship history for MSHA mine 4001829

Current hierarchy: **Schwab Charles F → Hawkeye Elkhorn Coal Company Inc → No 1**

- 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:** Schwab Charles F → No 1; 1975-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hawkeye Elkhorn Coal Company Inc → No 1; 1975-09-01 to 1976-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Schwab Charles F → Hawkeye Elkhorn Coal Company Inc; 1975-09-01 to 1976-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Rocky Top Coal Company → No 1; 1976-10-01 to 1979-05-14; source msha-controller-operator-history
- **controller_controls_mine:** Orange James E → No 1; 1976-10-01 to 1979-05-14; source msha-controller-operator-history
- **controller_controls_operator:** Orange James E → Rocky Top Coal Company; 1976-10-01 to 1979-05-14; source msha-controller-operator-history
- **operator_operates_mine:** Hawkeye Elkhorn Coal Company Inc → No 1; 1979-05-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schwab Charles F → Hawkeye Elkhorn Coal Company Inc; 1979-05-15 to current/open; source msha-controller-operator-history