# Relationship history for MSHA mine 0101089

Current hierarchy: **Thornton Irma Jean → Sumco Inc → Hilliard No 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:** Thornton Irma Jean → Hilliard No 2; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Trotter Jack → Hilliard No 2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Trotter Coal Co → Hilliard No 2; 1973-05-01 to 1974-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Trotter Jack → Trotter Coal Co; 1973-05-01 to 1974-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Sumco Inc → Hilliard No 2; 1974-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thornton Irma Jean → Sumco Inc; 1974-04-01 to current/open; source msha-controller-operator-history