# Relationship history for MSHA mine 2200615

Current hierarchy: **Ladner W N Jr → Ladner Brothers Sand & Gravel Inc → Ladner Pit #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:** Ladner W N Jr → Ladner Pit #2; 1985-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ladner Brothers Sand & Gravel Inc → Ladner Pit #2; 1989-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ladner W N Jr → Ladner Brothers Sand & Gravel Inc; 1989-10-01 to current/open; source msha-controller-operator-history