# Relationship history for MSHA mine 1516726

Current hierarchy: **Mounts Lester → Mary Mounts Coal Company Inc → No 1 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Mounts Lester → No 1 Surface; 1977-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mary Mounts Coal Company Inc → No 1 Surface; 1989-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mounts Lester → Mary Mounts Coal Company Inc; 1989-09-01 to current/open; source msha-controller-operator-history