# Relationship history for MSHA mine 2302450

Current hierarchy: **Norman D  Land; Brittany M  Boyle → Dry Valley Sand And Gravel → Dry Valley 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Dry Valley Enterprise Inc → Dry Valley Sand And Gravel; 2013-05-05 to 2017-06-05; source msha-controller-operator-history
- **controller_controls_mine:** Mike V  Elwood et al → Dry Valley Sand And Gravel; 2013-05-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mike V  Elwood et al → Dry Valley Enterprise Inc; 2013-05-05 to 2017-06-05; source msha-controller-operator-history
- **controller_controls_operator:** Sally A  Elwood et al → Dry Valley Enterprise Inc; 2013-05-05 to 2017-06-05; source msha-controller-operator-history
- **operator_operates_mine:** Dry Valley Sand And Gravel → Dry Valley Sand And Gravel; 2017-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Norman D  Land et al → Dry Valley Sand And Gravel; 2017-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norman D  Land et al → Dry Valley Sand And Gravel; 2017-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brittany M  Boyle et al → Dry Valley Sand And Gravel; 2017-06-06 to current/open; source msha-controller-operator-history