# Relationship history for MSHA mine 1511550

Current hierarchy: **Collins Roger B → Collins & May Mining Company Inc → Mine 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:** Collins Roger B → Mine No 1; 1974-12-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lester Robert-Charles Robert Stump-Bobby Blankensh → Mine No 1; 1977-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** L S B Coal Company → Mine No 1; 1978-08-01 to 1980-06-22; source msha-controller-operator-history
- **controller_controls_operator:** Lester Robert-Charles Robert Stump-Bobby Blankensh → L S B Coal Company; 1978-08-01 to 1980-06-22; source msha-controller-operator-history
- **operator_operates_mine:** R V & W Mining Inc → Mine No 1; 1980-06-23 to 1981-05-18; source msha-controller-operator-history
- **controller_controls_mine:** Ratliff Blake → Mine No 1; 1980-06-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ratliff Blake → R V & W Mining Inc; 1980-06-23 to 1981-05-18; source msha-controller-operator-history
- **controller_controls_mine:** Reynolds Craig → Mine No 1; 1981-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Justice Mining Inc → Mine No 1; 1981-05-19 to 1990-03-18; source msha-controller-operator-history
- **controller_controls_operator:** Reynolds Craig → Justice Mining Inc; 1981-05-19 to 1990-03-18; source msha-controller-operator-history
- **operator_operates_mine:** Collins & May Mining Company Inc → Mine No 1; 1990-03-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Collins Roger B → Collins & May Mining Company Inc; 1990-03-19 to current/open; source msha-controller-operator-history