# Relationship history for MSHA mine 4001755

Current hierarchy: **Rast Cleborn R → Kennory Coal Company → Underground Mine #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

- **operator_operates_mine:** Big A Equipment Company Inc → Underground Mine #1; 1975-01-01 to 1975-07-22; source msha-controller-operator-history
- **controller_controls_mine:** Mc Daniel Aster → Underground Mine #1; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Daniel Aster → Big A Equipment Company Inc; 1975-01-01 to 1975-07-22; source msha-controller-operator-history
- **operator_operates_mine:** Big A Equipment Company → Underground Mine #1; 1975-07-23 to 1977-01-06; source msha-controller-operator-history
- **controller_controls_mine:** Mc Daniel Irvin → Underground Mine #1; 1975-07-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Daniel Irvin → Big A Equipment Company; 1975-07-23 to 1977-01-06; source msha-controller-operator-history
- **operator_operates_mine:** Middle Mountain Coal Company → Underground Mine #1; 1977-01-07 to 1978-02-27; source msha-controller-operator-history
- **controller_controls_mine:** Helm James → Underground Mine #1; 1977-01-07 to 1978-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Helm James → Middle Mountain Coal Company; 1977-01-07 to 1978-02-27; source msha-controller-operator-history
- **operator_operates_mine:** Kennory Coal Company → Underground Mine #1; 1978-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rast Cleborn R → Underground Mine #1; 1978-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rast Cleborn R → Kennory Coal Company; 1978-02-28 to current/open; source msha-controller-operator-history