# Relationship history for MSHA mine 3304048

Current hierarchy: **Theodore L  Darlington → Waterloo Coal Company Inc → Waterloo Dock #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** La May Industries Inc → Waterloo Dock #1; 1986-05-01 to 1988-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Phil A  Bowman  et al → Waterloo Dock #1; 1986-05-01 to 1988-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Phil A  Bowman  et al → La May Industries Inc; 1986-05-01 to 1988-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Waterloo Coal Company Inc → Waterloo Dock #1; 1988-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Theodore L  Darlington → Waterloo Dock #1; 1988-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Theodore L  Darlington → Waterloo Coal Company Inc; 1988-10-01 to current/open; source msha-controller-operator-history