# Relationship history for MSHA mine 3603508

Current hierarchy: **Glasgow Inc → Lehigh Asphalt Paving & Construction Co → Lehigh Asphalt Paving & Construction Co**

- 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:** Refractory Sand Company Inc → Lehigh Asphalt Paving & Construction Co; 1950-01-01 to 1997-08-12; source msha-controller-operator-history
- **controller_controls_mine:** Luther T Blew Contracting Company Inc → Lehigh Asphalt Paving & Construction Co; 1950-01-01 to 1997-08-12; source msha-controller-operator-history
- **controller_controls_operator:** Luther T Blew Contracting Company Inc → Refractory Sand Company Inc; 1950-01-01 to 1997-08-12; source msha-controller-operator-history
- **controller_controls_mine:** Glasgow Inc → Lehigh Asphalt Paving & Construction Co; 1996-01-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lehigh Asphalt Paving & Construction Co → Lehigh Asphalt Paving & Construction Co; 1997-08-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Glasgow Inc → Lehigh Asphalt Paving & Construction Co; 1997-08-13 to current/open; source msha-controller-operator-history