# Relationship history for MSHA mine 1513508

Current hierarchy: **Stanford Energy → Triple Elkhorn Mining Company Inc → No 2 Surface**

- 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:** Zapata Corp → No 2 Surface; 1977-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Triple Elkhorn Mining Company Inc → No 2 Surface; 1982-05-01 to 1983-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Zapata Corp → Triple Elkhorn Mining Company Inc; 1982-05-01 to 1983-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Triple Elkhorn Mining Company Inc → No 2 Surface; 1983-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Stanford Energy → No 2 Surface; 1983-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stanford Energy → Triple Elkhorn Mining Company Inc; 1983-07-01 to current/open; source msha-controller-operator-history