# Relationship history for MSHA mine 0203176

Current hierarchy: **Donald  Gagnon → Gagnons Sand & Gravel → Combs Materials DBA Gagnons Sand & Grave**

- 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:** Vista Materials → Combs Materials DBA Gagnons Sand & Grave; 2007-07-24 to 2009-04-08; source msha-controller-operator-history
- **controller_controls_mine:** HC Landings LLC → Combs Materials DBA Gagnons Sand & Grave; 2007-07-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** HC Landings LLC → Vista Materials; 2007-07-24 to 2009-04-08; source msha-controller-operator-history
- **operator_operates_mine:** Gagnons Sand & Gravel → Combs Materials DBA Gagnons Sand & Grave; 2009-04-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Donald  Gagnon → Combs Materials DBA Gagnons Sand & Grave; 2009-04-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donald  Gagnon → Gagnons Sand & Gravel; 2009-04-09 to current/open; source msha-controller-operator-history