# Relationship history for MSHA mine 1512351

Current hierarchy: **Bowling Jess & Bobby → Pine Knot Coal Company → No 1 Strip**

- 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:** American Viking Contractors Inc → No 1 Strip; 1978-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** American Viking Contractors Inc → No 1 Strip; 1980-05-01 to 1982-01-18; source msha-controller-operator-history
- **controller_controls_operator:** American Viking Contractors Inc → American Viking Contractors Inc; 1980-05-01 to 1982-01-18; source msha-controller-operator-history
- **operator_operates_mine:** Pine Knot Coal Company → No 1 Strip; 1982-01-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bowling Jess & Bobby → No 1 Strip; 1982-01-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bowling Jess & Bobby → Pine Knot Coal Company; 1982-01-19 to current/open; source msha-controller-operator-history