# Relationship history for MSHA mine 4604811

Current hierarchy: **Coal Arbed → Hull Coal Corp → Mine No 6**

- 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:** Hard Rock Coal Company → Mine No 6; 1975-06-01 to 1978-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Cline Charles-Robert Lockhart Et Al → Mine No 6; 1975-06-01 to 1978-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Cline Charles-Robert Lockhart Et Al → Hard Rock Coal Company; 1975-06-01 to 1978-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Coal Arbed → Mine No 6; 1976-07-18 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hull Coal Corp → Mine No 6; 1978-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Coal Arbed → Hull Coal Corp; 1978-05-01 to current/open; source msha-controller-operator-history