# Relationship history for MSHA mine 3901378

Current hierarchy: **Falzerano Theresa → Dakota Sand & Gravel Inc → DAKOTA SAND AND GRAVEL**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** T & D Construction → DAKOTA SAND AND GRAVEL; 1990-06-01 to 1995-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Falzerano Alvin → DAKOTA SAND AND GRAVEL; 1990-06-01 to 1995-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Falzerano Alvin → T & D Construction; 1990-06-01 to 1995-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Dakota Sand & Gravel Inc → DAKOTA SAND AND GRAVEL; 1995-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Falzerano Theresa → DAKOTA SAND AND GRAVEL; 1995-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Falzerano Theresa → Dakota Sand & Gravel Inc; 1995-06-01 to current/open; source msha-controller-operator-history