# Relationship history for MSHA mine 1512059

Current hierarchy: **Petersville Sleigh Ltd → Western Engineering Inc → Rockport Terminal**

- 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:** Western Engineering Inc → Rockport Terminal; 1979-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Petersville Sleigh Ltd Et Al → Rockport Terminal; 1979-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Petersville Sleigh Ltd Et Al → Western Engineering Inc; 1979-10-01 to current/open; source msha-controller-operator-history