# Relationship history for MSHA mine 2601489

Current hierarchy: **Tim E  Bertagnolli → T E Bertagnolli & Associates → LOCKWOOD 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:** American Aggregate Inc → LOCKWOOD PIT; 1978-03-09 to 1995-09-30; source msha-controller-operator-history
- **controller_controls_mine:** American Aggregate Inc → LOCKWOOD PIT; 1978-03-09 to 1995-09-30; source msha-controller-operator-history
- **controller_controls_operator:** American Aggregate Inc → American Aggregate Inc; 1978-03-09 to 1995-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Tim E  Bertagnolli → LOCKWOOD PIT; 1987-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** T E Bertagnolli & Associates → LOCKWOOD PIT; 1995-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tim E  Bertagnolli → T E Bertagnolli & Associates; 1995-10-01 to current/open; source msha-controller-operator-history