# Relationship history for MSHA mine 4104989

Current hierarchy: **Robert Charles  Mumme → Dryden Stone  Co. Inc. → Rock 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:** Dryden Stone  Co. Inc. → Rock Quarry; 2012-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert Charles  Mumme → Rock Quarry; 2012-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert Charles  Mumme → Dryden Stone  Co. Inc.; 2012-12-12 to current/open; source msha-controller-operator-history