# Relationship history for MSHA mine 1511233

Current hierarchy: **Hurley Bruce → Carol Dale Mining → 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:** Curtis  Francis → No 1; 1971-11-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Big Hill Coal Company → No 1; 1978-04-01 to 1986-01-09; source msha-controller-operator-history
- **controller_controls_operator:** Curtis  Francis → Big Hill Coal Company; 1978-04-01 to 1986-01-09; source msha-controller-operator-history
- **operator_operates_mine:** Big Ugly Coal Company Inc → No 1; 1986-01-10 to 1988-07-28; source msha-controller-operator-history
- **controller_controls_mine:** Blackburn Lawyer → No 1; 1986-01-10 to 1988-07-28; source msha-controller-operator-history
- **controller_controls_operator:** Blackburn Lawyer → Big Ugly Coal Company Inc; 1986-01-10 to 1988-07-28; source msha-controller-operator-history
- **operator_operates_mine:** Carol Dale Mining → No 1; 1988-07-29 to 1989-08-23; source msha-controller-operator-history
- **controller_controls_mine:** Slater Gary Et Al → No 1; 1988-07-29 to 1989-08-23; source msha-controller-operator-history
- **controller_controls_operator:** Slater Gary Et Al → Carol Dale Mining; 1988-07-29 to 1989-08-23; source msha-controller-operator-history
- **operator_operates_mine:** Carol Dale Mining → No 1; 1989-08-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hurley Bruce → No 1; 1989-08-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hurley Bruce → Carol Dale Mining; 1989-08-24 to current/open; source msha-controller-operator-history