# Relationship history for MSHA mine 3606449

Current hierarchy: **Smith Lester E → Lester E Smith Coal Company → Smith Strips**

- 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:** Lester E Smith Coal Company → Smith Strips; 1977-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith Lester E → Smith Strips; 1977-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Lester E → Lester E Smith Coal Company; 1977-06-01 to current/open; source msha-controller-operator-history