# Relationship history for MSHA mine 1600959

Current hierarchy: **Smith Gladys D → Accardo-Deutsch Material → Accardo-Deutsch Material**

- 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:** Humphrey L L & Duane → Accardo-Deutsch Material; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** L L Humphrey & Son → Accardo-Deutsch Material; 1979-01-01 to 1979-11-27; source msha-controller-operator-history
- **controller_controls_operator:** Humphrey L L & Duane → L L Humphrey & Son; 1979-01-01 to 1979-11-27; source msha-controller-operator-history
- **operator_operates_mine:** Tschirn Farms Inc → Accardo-Deutsch Material; 1979-11-28 to 1981-07-26; source msha-controller-operator-history
- **controller_controls_mine:** Tschirn Darryl → Accardo-Deutsch Material; 1979-11-28 to 1981-07-26; source msha-controller-operator-history
- **controller_controls_operator:** Tschirn Darryl → Tschirn Farms Inc; 1979-11-28 to 1981-07-26; source msha-controller-operator-history
- **operator_operates_mine:** Accardo-Deutsch Material → Accardo-Deutsch Material; 1981-07-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith Gladys D → Accardo-Deutsch Material; 1981-07-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Gladys D → Accardo-Deutsch Material; 1981-07-27 to current/open; source msha-controller-operator-history