# Relationship history for MSHA mine 3303790

Current hierarchy: **Keim Bill → Tap Resources Inc → Tap Mine**

- 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:** Delta Energy Inc → Tap Mine; 1979-11-01 to 1982-03-24; source msha-controller-operator-history
- **controller_controls_mine:** Schlabach Alvin A → Tap Mine; 1979-11-01 to 1982-03-24; source msha-controller-operator-history
- **controller_controls_operator:** Schlabach Alvin A → Delta Energy Inc; 1979-11-01 to 1982-03-24; source msha-controller-operator-history
- **operator_operates_mine:** Tap Resources Inc → Tap Mine; 1982-03-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Keim Bill → Tap Mine; 1982-03-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keim Bill → Tap Resources Inc; 1982-03-25 to current/open; source msha-controller-operator-history