# Relationship history for MSHA mine 2901755

Current hierarchy: **Collier Joe F → Collier Construction Company → Collier Pit**

- 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:** Collier Construction Company → Collier Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Collier Joe F → Collier Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Collier Joe F → Collier Construction Company; 1979-01-01 to current/open; source msha-controller-operator-history