# Relationship history for MSHA mine 1200897

Current hierarchy: **West Joe → West Coal Company → West Strip**

- 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:** Blanton Coal Company → West Strip; 1950-01-01 to 1974-02-22; source msha-controller-operator-history
- **controller_controls_mine:** Blanton Kenneth → West Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blanton Kenneth → Blanton Coal Company; 1950-01-01 to 1974-02-22; source msha-controller-operator-history
- **operator_operates_mine:** West Coal Company → West Strip; 1974-02-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** West Joe → West Strip; 1974-02-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** West Joe → West Coal Company; 1974-02-23 to current/open; source msha-controller-operator-history