# Relationship history for MSHA mine 2402707

Current hierarchy: **Megan  Biggs; Chyan  Biggs → Big Sky Boulder Supply, Inc → Edgar Quarry**

- 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:** Big Sky Boulder Supply, Inc → Edgar Quarry; 2017-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Chyan  Biggs et al → Edgar Quarry; 2017-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chyan  Biggs et al → Big Sky Boulder Supply, Inc; 2017-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Megan  Biggs et al → Big Sky Boulder Supply, Inc; 2017-02-17 to current/open; source msha-controller-operator-history