# Relationship history for MSHA mine 1509611

Current hierarchy: **Coffey Jack → J & B Tipple Inc → Prep Plant**

- 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:** Black Ridge Coal Company Inc → Prep Plant; 1976-01-01 to 1977-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Lowery Joseph A → Prep Plant; 1976-01-01 to 1977-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Lowery Joseph A → Black Ridge Coal Company Inc; 1976-01-01 to 1977-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Daniel Boone Coal Company Inc → Prep Plant; 1977-04-01 to 1979-07-15; source msha-controller-operator-history
- **controller_controls_mine:** Lockhart Peter R → Prep Plant; 1977-04-01 to 1979-07-15; source msha-controller-operator-history
- **controller_controls_operator:** Lockhart Peter R → Daniel Boone Coal Company Inc; 1977-04-01 to 1979-07-15; source msha-controller-operator-history
- **operator_operates_mine:** Cactus Coal Corp → Prep Plant; 1979-07-16 to 1986-12-16; source msha-controller-operator-history
- **controller_controls_mine:** Slobaugh Fredric → Prep Plant; 1979-07-16 to 1986-12-16; source msha-controller-operator-history
- **controller_controls_operator:** Slobaugh Fredric → Cactus Coal Corp; 1979-07-16 to 1986-12-16; source msha-controller-operator-history
- **controller_controls_mine:** Coffey Jack Et Al → Prep Plant; 1980-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** J & B Tipple Inc → Prep Plant; 1986-12-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Coffey Jack Et Al → J & B Tipple Inc; 1986-12-17 to current/open; source msha-controller-operator-history