# Relationship history for MSHA mine 2401978

Current hierarchy: **Mockel John → Concrete Septic Tank Company → A/W SCREENING PLANT #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:** Concrete Septic Tank Company → A/W SCREENING PLANT #1; 1992-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mockel John Et Al → A/W SCREENING PLANT #1; 1992-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mockel John Et Al → Concrete Septic Tank Company; 1992-08-01 to current/open; source msha-controller-operator-history