# Relationship history for MSHA mine 4801605

Current hierarchy: **John E  Melgaard Jr → Melgaard Construction Company Incorporated → Rock Crusher #2**

- 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

- **controller_controls_mine:** John E  Melgaard Sr. → Rock Crusher #2; 2001-09-01 to 2018-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Melgaard Construction Company Incorporated → Rock Crusher #2; 2001-09-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John E  Melgaard Sr. → Melgaard Construction Company Incorporated; 2001-09-20 to 2018-09-30; source msha-controller-operator-history
- **controller_controls_mine:** John E  Melgaard Jr → Rock Crusher #2; 2018-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John E  Melgaard Jr → Melgaard Construction Company Incorporated; 2018-10-01 to current/open; source msha-controller-operator-history