# Relationship history for MSHA mine 1516465

Current hierarchy: **Frost Andrew → Andy Frost Coal Company Inc → Saxton 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

- **controller_controls_mine:** Frost Andrew → Saxton Mine; 1981-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Andy Frost Coal Company Inc → Saxton Mine; 1988-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Frost Andrew → Andy Frost Coal Company Inc; 1988-08-01 to current/open; source msha-controller-operator-history