# Relationship history for MSHA mine 4500699

Current hierarchy: **Mark  Doubravsky → Mark'S Pyramid Concrete & Construction → THOMPSON QUARRY**

- 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:** Stanley Thompson Company → THOMPSON QUARRY; 1950-01-01 to 1984-08-19; source msha-controller-operator-history
- **controller_controls_mine:** Stanley  Thompson → THOMPSON QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stanley  Thompson → Stanley Thompson Company; 1950-01-01 to 1984-08-19; source msha-controller-operator-history
- **operator_operates_mine:** Mark'S Pyramid Concrete & Construction → THOMPSON QUARRY; 1984-08-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mark  Doubravsky → THOMPSON QUARRY; 1984-08-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark  Doubravsky → Mark'S Pyramid Concrete & Construction; 1984-08-20 to current/open; source msha-controller-operator-history