# Relationship history for MSHA mine 4503805

Current hierarchy: **Randall  Davis; Sharon  Davis; Brian  Davis → May Valley Sand and Gravel → Extec Crusher**

- 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:** May Valley Sand and Gravel → Extec Crusher; 2020-08-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Brian  Davis et al → Extec Crusher; 2020-08-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brian  Davis et al → May Valley Sand and Gravel; 2020-08-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Randall  Davis et al → May Valley Sand and Gravel; 2020-08-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sharon  Davis et al → May Valley Sand and Gravel; 2020-08-27 to current/open; source msha-controller-operator-history