# Relationship history for MSHA mine 3304415

Current hierarchy: **Mary A  Bussert; Gary A  Bussert → Three Locks Gravel Co. → Three Locks Gravel Co.**

- 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:** Three Locks Sand & Gravel → Three Locks Gravel Co.; 1998-03-01 to 2000-08-06; source msha-controller-operator-history
- **controller_controls_mine:** Triunity Corp → Three Locks Gravel Co.; 1998-03-01 to 2000-08-06; source msha-controller-operator-history
- **controller_controls_operator:** Triunity Corp → Three Locks Sand & Gravel; 1998-03-01 to 2000-08-06; source msha-controller-operator-history
- **operator_operates_mine:** Three Locks Gravel Co. → Three Locks Gravel Co.; 2000-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gary A  Bussert et al → Three Locks Gravel Co.; 2000-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary A  Bussert et al → Three Locks Gravel Co.; 2000-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mary A  Bussert et al → Three Locks Gravel Co.; 2000-08-07 to current/open; source msha-controller-operator-history