# Relationship history for MSHA mine 1506315

Current hierarchy: **Young F W → F W Young Construction Company → 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:** Sun Ray Coal Company → No 1 Surface; 1973-01-01 to 1976-10-12; source msha-controller-operator-history
- **controller_controls_mine:** Sun Ray Coal Company → No 1 Surface; 1973-01-01 to 1976-10-12; source msha-controller-operator-history
- **controller_controls_operator:** Sun Ray Coal Company → Sun Ray Coal Company; 1973-01-01 to 1976-10-12; source msha-controller-operator-history
- **operator_operates_mine:** F W Young Construction Company → No 1 Surface; 1976-10-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Young F W → No 1 Surface; 1976-10-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Young F W → F W Young Construction Company; 1976-10-13 to current/open; source msha-controller-operator-history