# Relationship history for MSHA mine 1505382

Current hierarchy: **Reed Billy → Spencer Branch Coal Company Inc → No I-20 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:** Ligon Preparation Company → No I-20 Mine; 1950-01-01 to 1974-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Hall Hargis → No I-20 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hall Hargis → Ligon Preparation Company; 1950-01-01 to 1974-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Spencer Branch Coal Company Inc → No I-20 Mine; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Reed Billy → No I-20 Mine; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Reed Billy → Spencer Branch Coal Company Inc; 1975-01-01 to current/open; source msha-controller-operator-history