# Relationship history for MSHA mine 4403785

Current hierarchy: **West Thomas H & James A Brown → Brown & West Coal Company → No 1 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:** Laguna Mining Company → No 1 Strip; 1973-01-01 to 1975-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Roberts Joe H & Thomas H West → No 1 Strip; 1973-01-01 to 1975-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Roberts Joe H & Thomas H West → Laguna Mining Company; 1973-01-01 to 1975-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Brown & West Coal Company → No 1 Strip; 1976-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** West Thomas H & James A Brown → No 1 Strip; 1976-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** West Thomas H & James A Brown → Brown & West Coal Company; 1976-01-01 to current/open; source msha-controller-operator-history