# Relationship history for MSHA mine 3605897

Current hierarchy: **Wehry Thomas-Daniel & Carl → W & B Coal Company → No 2 Slope**

- 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:** W & S Coal Company → No 2 Slope; 1975-12-05 to 1976-07-27; source msha-controller-operator-history
- **controller_controls_mine:** Wehry Carl & Irvin E Mace → No 2 Slope; 1975-12-05 to 1976-07-27; source msha-controller-operator-history
- **controller_controls_operator:** Wehry Carl & Irvin E Mace → W & S Coal Company; 1975-12-05 to 1976-07-27; source msha-controller-operator-history
- **operator_operates_mine:** W & B Coal Company → No 2 Slope; 1976-07-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Wehry Thomas-Daniel & Carl → No 2 Slope; 1976-07-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wehry Thomas-Daniel & Carl → W & B Coal Company; 1976-07-28 to current/open; source msha-controller-operator-history