# Relationship history for MSHA mine 2700074

Current hierarchy: **Boston Sand & Gravel Company → Ossipee Aggregates Corp → Ossipee Aggregates**

- 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:** Ossipee Aggregates Corp → Ossipee Aggregates; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Boston Sand & Gravel Company → Ossipee Aggregates; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Boston Sand & Gravel Company → Ossipee Aggregates Corp; 1950-01-01 to current/open; source msha-controller-operator-history