# Relationship history for MSHA mine 1901069

Current hierarchy: **Samantha  Dellaghelfa → Greylock Sand & Gravel, LLC → Greylock Sand and Gravel**

- 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:** Della Concrete Corporation → Greylock Sand and Gravel; 1999-07-01 to 2013-11-25; source msha-controller-operator-history
- **controller_controls_mine:** Norman  Dellaghelfa Sr  et al → Greylock Sand and Gravel; 1999-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norman  Dellaghelfa Sr  et al → Della Concrete Corporation; 1999-07-01 to 2013-11-25; source msha-controller-operator-history
- **controller_controls_operator:** Alan  Dellaghelfa  et al → Della Concrete Corporation; 1999-07-01 to 2013-11-25; source msha-controller-operator-history
- **operator_operates_mine:** Greylock Sand & Gravel, LLC → Greylock Sand and Gravel; 2013-11-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Samantha  Dellaghelfa → Greylock Sand and Gravel; 2013-11-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Samantha  Dellaghelfa → Greylock Sand & Gravel, LLC; 2013-11-26 to current/open; source msha-controller-operator-history