# Relationship history for MSHA mine 1512672

Current hierarchy: **Florida Progress Corporation → Kentucky May Coal Company Inc → Dredge #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

- **operator_operates_mine:** Louisa Sand & Gravel Company Inc → Dredge #3; 1980-12-01 to 1989-12-21; source msha-controller-operator-history
- **controller_controls_mine:** Wilson Gene A → Dredge #3; 1980-12-01 to 1989-12-21; source msha-controller-operator-history
- **controller_controls_operator:** Wilson Gene A → Louisa Sand & Gravel Company Inc; 1980-12-01 to 1989-12-21; source msha-controller-operator-history
- **controller_controls_mine:** Florida Progress Corporation → Dredge #3; 1989-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kentucky May Coal Company Inc → Dredge #3; 1989-12-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Florida Progress Corporation → Kentucky May Coal Company Inc; 1989-12-22 to current/open; source msha-controller-operator-history