# Relationship history for MSHA mine 0500991

Current hierarchy: **John L  Ary → Hard Rock Paving & Redi-Mix Inc → Ulrich Pit Hard Rock #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Hart Rok Redi-Mixt Concrete Inc → Ulrich Pit Hard Rock #1; 1950-01-01 to 1982-08-16; source msha-controller-operator-history
- **controller_controls_mine:** Long Donald K Sr → Ulrich Pit Hard Rock #1; 1950-01-01 to 1982-08-16; source msha-controller-operator-history
- **controller_controls_operator:** Long Donald K Sr → Hart Rok Redi-Mixt Concrete Inc; 1950-01-01 to 1982-08-16; source msha-controller-operator-history
- **operator_operates_mine:** Hard Rock Paving & Redi-Mix Inc → Ulrich Pit Hard Rock #1; 1982-08-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John L  Ary → Ulrich Pit Hard Rock #1; 1982-08-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John L  Ary → Hard Rock Paving & Redi-Mix Inc; 1982-08-17 to current/open; source msha-controller-operator-history