# Relationship history for MSHA mine 3603986

Current hierarchy: **Millard R  Swank; Harold T  Swank → Three S Coal Company → Swank #1 Strip**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Three S Coal Company → Swank #1 Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Harold T  Swank et al → Swank #1 Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harold T  Swank et al → Three S Coal Company; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Millard R  Swank et al → Three S Coal Company; 1950-01-01 to current/open; source msha-controller-operator-history