# Relationship history for MSHA mine 2500755

Current hierarchy: **Janicek Melvin → J & J Company → J & J Company**

- 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:** E-Z Sand & Gravel Inc → J & J Company; 1950-01-01 to 1981-03-25; source msha-controller-operator-history
- **controller_controls_mine:** Zeller Gordon → J & J Company; 1950-01-01 to 1981-03-25; source msha-controller-operator-history
- **controller_controls_operator:** Zeller Gordon → E-Z Sand & Gravel Inc; 1950-01-01 to 1981-03-25; source msha-controller-operator-history
- **operator_operates_mine:** J & J Company → J & J Company; 1981-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Janicek Melvin → J & J Company; 1981-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Janicek Melvin → J & J Company; 1981-03-26 to current/open; source msha-controller-operator-history