# Relationship history for MSHA mine 4801904

Current hierarchy: **John E  Melgaard Jr → Melgaard Construction Co., Inc → ASTEC 2512K FOLD & GO SP001 093075**

- 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

- **controller_controls_mine:** John E  Melgaard Sr. → ASTEC 2512K FOLD & GO SP001 093075; 2001-09-01 to 2018-09-30; source msha-controller-operator-history
- **controller_controls_mine:** John E  Melgaard Jr → ASTEC 2512K FOLD & GO SP001 093075; 2018-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Melgaard Construction Co., Inc → ASTEC 2512K FOLD & GO SP001 093075; 2025-09-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John E  Melgaard Jr → Melgaard Construction Co., Inc; 2025-09-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John E  Melgaard Sr. → Melgaard Construction Co., Inc; 2025-09-25 to 2018-09-30; source msha-controller-operator-history