# Relationship history for MSHA mine 1401160

Current hierarchy: **Jay R  Lyon; Melvin L  Lyon → Lyon Rock Quarry → Lyon Rock 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:** Lyon Rock Quarry → Lyon Rock Quarry; 1950-01-01 to 2008-05-09; source msha-controller-operator-history
- **controller_controls_mine:** Melvin L  Lyon → Lyon Rock Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Melvin L  Lyon → Lyon Rock Quarry; 1950-01-01 to 2008-05-09; source msha-controller-operator-history
- **operator_operates_mine:** Lyon Rock Quarry → Lyon Rock Quarry; 2008-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jay R  Lyon et al → Lyon Rock Quarry; 2008-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jay R  Lyon et al → Lyon Rock Quarry; 2008-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Melvin L  Lyon et al → Lyon Rock Quarry; 2008-05-10 to current/open; source msha-controller-operator-history