# Relationship history for MSHA mine 4201284

Current hierarchy: **Higgins John → Summit Minerals Inc → Blackhawk**

- 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:** Utah Coal & Energy Inc → Blackhawk; 1976-02-01 to 1986-10-19; source msha-controller-operator-history
- **controller_controls_mine:** Cafarelli C G → Blackhawk; 1976-02-01 to 1986-10-19; source msha-controller-operator-history
- **controller_controls_operator:** Cafarelli C G → Utah Coal & Energy Inc; 1976-02-01 to 1986-10-19; source msha-controller-operator-history
- **operator_operates_mine:** Summit Minerals Inc → Blackhawk; 1986-10-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Higgins John → Blackhawk; 1986-10-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Higgins John → Summit Minerals Inc; 1986-10-20 to current/open; source msha-controller-operator-history