# Relationship history for MSHA mine 1508762

Current hierarchy: **Peffer John G → K & M Trucking Company Inc → No 2 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Big Seam Coal Company Inc → No 2 Surface; 1975-06-01 to 1977-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Wendell B → No 2 Surface; 1975-06-01 to 1977-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Wendell B → Big Seam Coal Company Inc; 1975-06-01 to 1977-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Peffer John G → No 2 Surface; 1976-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** K & M Trucking Company Inc → No 2 Surface; 1977-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peffer John G → K & M Trucking Company Inc; 1977-09-01 to current/open; source msha-controller-operator-history