# Relationship history for MSHA mine 3303310

Current hierarchy: **Eckenrode Norbert J → Eckenrode Coal Co → Auger Mine No 19**

- 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

- **controller_controls_mine:** Aperfine Peter → Auger Mine No 19; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eckenrode Norbert J → Auger Mine No 19; 1972-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tri-State Coal Company Inc → Auger Mine No 19; 1975-03-01 to 1977-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Aperfine Peter → Tri-State Coal Company Inc; 1975-03-01 to 1977-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Eckenrode Coal Co → Auger Mine No 19; 1977-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eckenrode Norbert J → Eckenrode Coal Co; 1977-08-01 to current/open; source msha-controller-operator-history