# Relationship history for MSHA mine 4103673

Current hierarchy: **A Donovan  Smart → Smart Materials Inc → SMART 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

- **controller_controls_mine:** A Donovan  Smart et al → SMART PIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Smart Materials Inc → SMART PIT; 1991-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** A Donovan  Smart et al → Smart Materials Inc; 1991-05-01 to current/open; source msha-controller-operator-history