# Relationship history for MSHA mine 5001438

Current hierarchy: **Gira B F → Akminco → Bluff Mine**

- 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:** Bluff Mining Association → Bluff Mine; 1982-08-01 to 1985-07-14; source msha-controller-operator-history
- **controller_controls_mine:** Noel S  Tanner  et al → Bluff Mine; 1982-08-01 to 1985-07-14; source msha-controller-operator-history
- **controller_controls_operator:** Noel S  Tanner  et al → Bluff Mining Association; 1982-08-01 to 1985-07-14; source msha-controller-operator-history
- **operator_operates_mine:** Akminco → Bluff Mine; 1985-07-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gira B F → Bluff Mine; 1985-07-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gira B F → Akminco; 1985-07-15 to current/open; source msha-controller-operator-history