# Relationship history for MSHA mine 2002960

Current hierarchy: **Jenny A Vollmer → Vollmer Ready Mix Inc. → Alexander Pit**

- 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:** Vollmer Ready Mix Inc. → Alexander Pit; 1995-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dave  Vollmer → Alexander Pit; 1995-10-01 to 2014-06-04; source msha-controller-operator-history
- **controller_controls_operator:** Dave  Vollmer → Vollmer Ready Mix Inc.; 1995-10-01 to 2014-06-04; source msha-controller-operator-history
- **controller_controls_mine:** Audrey A  Vollmer → Alexander Pit; 2014-06-05 to 2026-09-09; source msha-controller-operator-history
- **controller_controls_operator:** Audrey A  Vollmer → Vollmer Ready Mix Inc.; 2014-06-05 to 2026-09-09; source msha-controller-operator-history
- **controller_controls_mine:** Jenny A Vollmer → Alexander Pit; 2026-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jenny A Vollmer → Vollmer Ready Mix Inc.; 2026-09-10 to current/open; source msha-controller-operator-history