# Relationship history for MSHA mine 1516585

Current hierarchy: **Curtis Robert J → Curtis Coal Company Inc → No 3**

- 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:** Salyers Frank Jr & Terry Cantrell → No 3; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Horton Steve → No 3; 1983-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ramblin Coal Company Inc → No 3; 1989-03-01 to 1989-07-23; source msha-controller-operator-history
- **controller_controls_operator:** Horton Steve → Ramblin Coal Company Inc; 1989-03-01 to 1989-07-23; source msha-controller-operator-history
- **operator_operates_mine:** Camp Fork Fuel Company Inc → No 3; 1989-07-24 to 1990-01-22; source msha-controller-operator-history
- **controller_controls_operator:** Salyers Frank Jr & Terry Cantrell → Camp Fork Fuel Company Inc; 1989-07-24 to 1990-01-22; source msha-controller-operator-history
- **operator_operates_mine:** Oakland Enterprises Inc → No 3; 1990-01-23 to 1991-07-25; source msha-controller-operator-history
- **controller_controls_mine:** James C  Ball → No 3; 1990-01-23 to 1991-07-25; source msha-controller-operator-history
- **controller_controls_operator:** James C  Ball → Oakland Enterprises Inc; 1990-01-23 to 1991-07-25; source msha-controller-operator-history
- **operator_operates_mine:** Dark Hill Enterprises Inc → No 3; 1991-07-26 to 1992-04-02; source msha-controller-operator-history
- **controller_controls_mine:** Blackburn Paul E → No 3; 1991-07-26 to 1992-04-02; source msha-controller-operator-history
- **controller_controls_operator:** Blackburn Paul E → Dark Hill Enterprises Inc; 1991-07-26 to 1992-04-02; source msha-controller-operator-history
- **operator_operates_mine:** Curtis Coal Company Inc → No 3; 1992-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Curtis Robert J → No 3; 1992-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Curtis Robert J → Curtis Coal Company Inc; 1992-04-03 to current/open; source msha-controller-operator-history