# Relationship history for MSHA mine 4500657

Current hierarchy: **Lakeside Industries Inc. → Martin Sand & Gravel → Martin Pit**

- 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:** Martin Sand & Gravel Inc → Martin Pit; 1950-01-01 to 1994-08-16; source msha-controller-operator-history
- **controller_controls_mine:** Douglas F  Martin et al → Martin Pit; 1950-01-01 to 1994-08-16; source msha-controller-operator-history
- **controller_controls_operator:** Douglas F  Martin et al → Martin Sand & Gravel Inc; 1950-01-01 to 1994-08-16; source msha-controller-operator-history
- **operator_operates_mine:** Martin Sand & Gravel Inc → Martin Pit; 1994-08-17 to 2012-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Michael  Lee et al → Martin Pit; 1994-08-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Lee et al → Martin Sand & Gravel Inc; 1994-08-17 to 2012-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Lakeside Industries Inc. et al → Martin Pit; 2008-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lakeside Industries Inc. → Martin Pit; 2012-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lakeside Industries Inc. et al → Lakeside Industries Inc.; 2012-04-01 to current/open; source msha-controller-operator-history