# Relationship history for MSHA mine 3101996

Current hierarchy: **Wayne  Cassavaugh → Carolina Sand Inc → Hannah Ferry Sand 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 Concrete Products Inc → Hannah Ferry Sand Pit; 1986-07-01 to 1996-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Harry  Tsumas → Hannah Ferry Sand Pit; 1986-07-01 to 1996-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Harry  Tsumas → American Concrete Products Inc; 1986-07-01 to 1996-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Unicon Concrete → Hannah Ferry Sand Pit; 1996-10-01 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Unicon Beton Inc → Hannah Ferry Sand Pit; 1996-10-01 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Unicon Beton Inc → Unicon Concrete; 1996-10-01 to 1999-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Carolina Sand Inc → Hannah Ferry Sand Pit; 1999-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Wayne  Cassavaugh → Hannah Ferry Sand Pit; 1999-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wayne  Cassavaugh → Carolina Sand Inc; 1999-04-01 to current/open; source msha-controller-operator-history