# Relationship history for MSHA mine 1507455

Current hierarchy: **Smith Lonnie & Eli → B & S Coal Company → No 27 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:** K & S Coal Company → No 27 Mine; 1974-01-01 to 1975-03-16; source msha-controller-operator-history
- **controller_controls_mine:** K & S Coal Co → No 27 Mine; 1974-01-01 to 1975-03-16; source msha-controller-operator-history
- **controller_controls_operator:** K & S Coal Co → K & S Coal Company; 1974-01-01 to 1975-03-16; source msha-controller-operator-history
- **operator_operates_mine:** B & S Coal Company → No 27 Mine; 1975-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith Lonnie & Eli → No 27 Mine; 1975-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Lonnie & Eli → B & S Coal Company; 1975-03-17 to current/open; source msha-controller-operator-history