# Relationship history for MSHA mine 1508199

Current hierarchy: **Farr Tommy → Contour Coal Company Inc → No 1 Surface 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:** Contour Coal Company Inc → No 1 Surface Mine; 1975-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Farr Tommy → No 1 Surface Mine; 1975-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Farr Tommy → Contour Coal Company Inc; 1975-04-03 to current/open; source msha-controller-operator-history