# Relationship history for MSHA mine 1509335

Current hierarchy: **Smith C M → Lee-Mar Coal Company Inc → No 2 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:** Ruebel George → No 2 Surface; 1975-04-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith C M → No 2 Surface; 1975-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ruecon Coal Inc → No 2 Surface; 1975-10-29 to 1976-09-26; source msha-controller-operator-history
- **controller_controls_operator:** Ruebel George → Ruecon Coal Inc; 1975-10-29 to 1976-09-26; source msha-controller-operator-history
- **operator_operates_mine:** Lee-Mar Coal Company Inc → No 2 Surface; 1976-09-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith C M → Lee-Mar Coal Company Inc; 1976-09-27 to current/open; source msha-controller-operator-history