# Relationship history for MSHA mine 3607757

Current hierarchy: **Schena William A - Andrew → S & S Coal Leasing Company → S & S #1**

- 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:** S & S Coal Leasing Company → S & S #1; 1985-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Schena William A - Andrew Et Al → S & S #1; 1985-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schena William A - Andrew Et Al → S & S Coal Leasing Company; 1985-11-01 to current/open; source msha-controller-operator-history