# Relationship history for MSHA mine 0102087

Current hierarchy: **Ronald Tyler Davis; Christopher Howard Davis → Davis Sand & Gravel → Cypress Pit**

- 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:** Davis Sand & Gravel → Cypress Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ronald H Davis → Cypress Pit; 1979-01-01 to 2023-02-19; source msha-controller-operator-history
- **controller_controls_operator:** Ronald H Davis → Davis Sand & Gravel; 1979-01-01 to 2023-02-19; source msha-controller-operator-history
- **controller_controls_mine:** Ronald Tyler Davis et al → Cypress Pit; 2023-02-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ronald Tyler Davis et al → Davis Sand & Gravel; 2023-02-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Christopher Howard Davis et al → Davis Sand & Gravel; 2023-02-20 to current/open; source msha-controller-operator-history