# Relationship history for MSHA mine 3503117

Current hierarchy: **George N  Lammi; Diane  Lammi-Massey → Lammi Sand & Rock Products → LAMMI PIT & PLANT**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Lammi Sand & Rock Products → LAMMI PIT & PLANT; 1983-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Diane  Lammi-Massey  et al → LAMMI PIT & PLANT; 1983-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Diane  Lammi-Massey  et al → Lammi Sand & Rock Products; 1983-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George N  Lammi et al → Lammi Sand & Rock Products; 1983-09-01 to current/open; source msha-controller-operator-history