# Relationship history for MSHA mine 3605859

Current hierarchy: **Ramaley Chalmers B → Ramaley Equipment & Supply Company → Ramaley 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

- **operator_operates_mine:** Ramaley Equipment & Supply Company → Ramaley Strip; 1950-01-01 to 1993-02-24; source msha-controller-operator-history
- **controller_controls_mine:** Ramaley Chalmers B → Ramaley Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ramaley Chalmers B → Ramaley Equipment & Supply Company; 1950-01-01 to 1993-02-24; source msha-controller-operator-history
- **operator_operates_mine:** Viking Coal Company Inc → Ramaley Strip; 1993-02-25 to 1993-09-06; source msha-controller-operator-history
- **controller_controls_mine:** Boyle Mark → Ramaley Strip; 1993-02-25 to 1993-09-06; source msha-controller-operator-history
- **controller_controls_operator:** Boyle Mark → Viking Coal Company Inc; 1993-02-25 to 1993-09-06; source msha-controller-operator-history
- **operator_operates_mine:** Ramaley Equipment & Supply Company → Ramaley Strip; 1993-09-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ramaley Chalmers B → Ramaley Equipment & Supply Company; 1993-09-07 to current/open; source msha-controller-operator-history