# Relationship history for MSHA mine 3401318

Current hierarchy: **Keeler Bruce → Keeler Quarry → Keeler Quarry And Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** James D  Schwarck → Keeler Quarry And Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Schwarck Quarries Inc → Keeler Quarry And Plant; 1981-05-01 to 1981-09-22; source msha-controller-operator-history
- **controller_controls_operator:** James D  Schwarck → Schwarck Quarries Inc; 1981-05-01 to 1981-09-22; source msha-controller-operator-history
- **operator_operates_mine:** Keeler Quarry → Keeler Quarry And Plant; 1981-09-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Keeler Bruce → Keeler Quarry And Plant; 1981-09-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keeler Bruce → Keeler Quarry; 1981-09-23 to current/open; source msha-controller-operator-history