# Relationship history for MSHA mine 1700892

Current hierarchy: **Toby J  Plummer → Plummer Excavation, Inc. → Granite Hill Quarry**

- 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:** Plummer Excavation, Inc. → Granite Hill Quarry; 2012-05-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Toby J  Plummer → Granite Hill Quarry; 2012-05-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Toby J  Plummer → Plummer Excavation, Inc.; 2012-05-03 to current/open; source msha-controller-operator-history