# Relationship history for MSHA mine 0503790

Current hierarchy: **Stewart Richard H → South Park Aggregates Inc → Fairplay 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Hulcher Aggregates Inc → Fairplay Quarry; 1982-08-01 to 1986-07-22; source msha-controller-operator-history
- **controller_controls_mine:** Hulcher Norman E → Fairplay Quarry; 1982-08-01 to 1986-07-22; source msha-controller-operator-history
- **controller_controls_operator:** Hulcher Norman E → Hulcher Aggregates Inc; 1982-08-01 to 1986-07-22; source msha-controller-operator-history
- **operator_operates_mine:** South Park Aggregates Inc → Fairplay Quarry; 1986-07-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Stewart Richard H → Fairplay Quarry; 1986-07-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stewart Richard H → South Park Aggregates Inc; 1986-07-23 to current/open; source msha-controller-operator-history