# Relationship history for MSHA mine 4604545

Current hierarchy: **Rag Aktiengesellschaft → Energy Development Corp → No 1 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

- **operator_operates_mine:** S S & B Machinery Inc → No 1 Surface; 1975-04-01 to 1977-10-12; source msha-controller-operator-history
- **controller_controls_mine:** Sundquist Arnold → No 1 Surface; 1975-04-01 to 1977-10-12; source msha-controller-operator-history
- **controller_controls_operator:** Sundquist Arnold → S S & B Machinery Inc; 1975-04-01 to 1977-10-12; source msha-controller-operator-history
- **controller_controls_mine:** Rag Aktiengesellschaft → No 1 Surface; 1976-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Energy Development Corp → No 1 Surface; 1977-10-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rag Aktiengesellschaft → Energy Development Corp; 1977-10-13 to current/open; source msha-controller-operator-history