# Relationship history for MSHA mine 3604269

Current hierarchy: **Zapata Corp → Doverspike Brothers Coal Company → Ringgold Mine**

- 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:** Doverspike Brothers Coal Company → Ringgold Mine; 1950-01-01 to 1976-01-09; source msha-controller-operator-history
- **controller_controls_mine:** Doverspike Brothers Coal Company → Ringgold Mine; 1950-01-01 to 1976-01-09; source msha-controller-operator-history
- **controller_controls_operator:** Doverspike Brothers Coal Company → Doverspike Brothers Coal Company; 1950-01-01 to 1976-01-09; source msha-controller-operator-history
- **operator_operates_mine:** Doverspike Brothers Coal Company → Ringgold Mine; 1976-01-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Zapata Corp → Ringgold Mine; 1976-01-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zapata Corp → Doverspike Brothers Coal Company; 1976-01-10 to current/open; source msha-controller-operator-history