# Relationship history for MSHA mine 4703256

Current hierarchy: **David  Mertens; Toni  Mertens → Mertens Sand & Gravel, LLC. → Mertens Sand & Gravel, LLC.**

- 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:** Mertens Sand & Gravel Llc → Mertens Sand & Gravel, LLC.; 2000-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Toni  Mertens  et al → Mertens Sand & Gravel, LLC.; 2000-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Toni  Mertens  et al → Mertens Sand & Gravel Llc; 2000-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Mertens  et al → Mertens Sand & Gravel Llc; 2000-12-01 to current/open; source msha-controller-operator-history