# Relationship history for MSHA mine 0404603

Current hierarchy: **Mc Broom Henry C → Mc Broom & Quigley → Big Mama**

- 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:** Mc Broom & Quigley → Big Mama; 1982-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mc Broom Henry C Et Al → Big Mama; 1982-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Broom Henry C Et Al → Mc Broom & Quigley; 1982-07-01 to current/open; source msha-controller-operator-history