# Relationship history for MSHA mine 1901093

Current hierarchy: **Robert  Cairns; Garry  Cairns → George R Cairns & Sons Inc → SHEDD BROOK 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** George R Cairns & Sons Inc → SHEDD BROOK SAND & GRAVEL, LLC.; 2000-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Garry  Cairns  et al → SHEDD BROOK SAND & GRAVEL, LLC.; 2000-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Garry  Cairns  et al → George R Cairns & Sons Inc; 2000-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Cairns  et al → George R Cairns & Sons Inc; 2000-09-01 to current/open; source msha-controller-operator-history