# Relationship history for MSHA mine 3608555

Current hierarchy: **John A  D'Amico → D'Amico Quarry Inc → D'AMICO QUARRY INC.**

- 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:** D'Amico Quarry Inc → D'AMICO QUARRY INC.; 1996-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John A  D'Amico → D'AMICO QUARRY INC.; 1996-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John A  D'Amico → D'Amico Quarry Inc; 1996-04-01 to current/open; source msha-controller-operator-history