# Relationship history for MSHA mine 0301431

Current hierarchy: **Tommy  Gipson → Tommy Gipson Construction Company → Duffield 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

- **controller_controls_mine:** Larry  Duffield et al → Duffield Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Souter Construction Company Inc → Duffield Quarry; 1979-01-01 to 1987-01-20; source msha-controller-operator-history
- **controller_controls_operator:** Larry  Duffield et al → Souter Construction Company Inc; 1979-01-01 to 1987-01-20; source msha-controller-operator-history
- **controller_controls_operator:** Randy  Duffield et al → Souter Construction Company Inc; 1979-01-01 to 1987-01-20; source msha-controller-operator-history
- **operator_operates_mine:** Tommy Gipson Construction Company → Duffield Quarry; 1987-01-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tommy  Gipson → Duffield Quarry; 1987-01-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tommy  Gipson → Tommy Gipson Construction Company; 1987-01-21 to current/open; source msha-controller-operator-history