# Relationship history for MSHA mine 1516771

Current hierarchy: **Medlin Allen → Natasha Trucking → 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:** Vaughn Bill → No 1 Strip; 1981-02-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Vaughn Construction → No 1 Strip; 1989-11-01 to 1990-04-22; source msha-controller-operator-history
- **controller_controls_operator:** Vaughn Bill → Vaughn Construction; 1989-11-01 to 1990-04-22; source msha-controller-operator-history
- **operator_operates_mine:** Natasha Trucking → No 1 Strip; 1990-04-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Medlin Allen → No 1 Strip; 1990-04-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Medlin Allen → Natasha Trucking; 1990-04-23 to current/open; source msha-controller-operator-history