# Relationship history for MSHA mine 2301823

Current hierarchy: **Dale  Parks; Bonnie  Parks → Parks Sand & Gravel → Parks Sand & 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

- **controller_controls_mine:** Sherman R  Odom → Parks Sand & Gravel; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Salem Ready-Mix Inc → Parks Sand & Gravel; 1980-12-01 to 1987-05-04; source msha-controller-operator-history
- **controller_controls_operator:** Sherman R  Odom → Salem Ready-Mix Inc; 1980-12-01 to 1987-05-04; source msha-controller-operator-history
- **operator_operates_mine:** Parks Sand & Gravel → Parks Sand & Gravel; 1987-05-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bonnie  Parks et al → Parks Sand & Gravel; 1987-05-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bonnie  Parks et al → Parks Sand & Gravel; 1987-05-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dale  Parks et al → Parks Sand & Gravel; 1987-05-05 to current/open; source msha-controller-operator-history