# Relationship history for MSHA mine 3606492

Current hierarchy: **Schlagle Frank → L T S Coal Company → Buck Slope 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:** L T S Coal Company → Buck Slope Mine; 1977-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Schlagle Frank Et Al → Buck Slope Mine; 1977-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schlagle Frank Et Al → L T S Coal Company; 1977-09-01 to current/open; source msha-controller-operator-history