# Relationship history for MSHA mine 0505162

Current hierarchy: **Burnco Rock Products Ltd → BURNCO Colorado LLC → Firestone Gravel Mine**

- 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

- **controller_controls_mine:** Bret  Hall et al → Firestone Gravel Mine; 2009-02-13 to 2017-02-26; source msha-controller-operator-history
- **controller_controls_mine:** Burnco Rock Products Ltd → Firestone Gravel Mine; 2017-02-27 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** BURNCO Colorado LLC → Firestone Gravel Mine; 2023-02-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bret  Hall et al → BURNCO Colorado LLC; 2023-02-16 to 2017-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Scott  Masi et al → BURNCO Colorado LLC; 2023-02-16 to 2017-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Burnco Rock Products Ltd → BURNCO Colorado LLC; 2023-02-16 to current/open; source msha-controller-operator-history