# Relationship history for MSHA mine 0102474

Current hierarchy: **MidAmerican Energy Holdings Company → Sand Mountain Minerals Inc → Pisgah No 2**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** MidAmerican Energy Holdings Company → Pisgah No 2; 1980-03-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sand Mountain Minerals Inc → Pisgah No 2; 1982-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MidAmerican Energy Holdings Company → Sand Mountain Minerals Inc; 1982-05-01 to current/open; source msha-controller-operator-history