# Relationship history for MSHA mine 4003433

Current hierarchy: **David  Stoltzfus; Arly  Kinniburgh → K & S Sand and Gravel → K & S 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Smith Stone → K & S Sand and Gravel; 2013-03-26 to 2019-04-21; source msha-controller-operator-history
- **controller_controls_mine:** Nyles  Smith → K & S Sand and Gravel; 2013-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nyles  Smith → Smith Stone; 2013-03-26 to 2019-04-21; source msha-controller-operator-history
- **operator_operates_mine:** K & S Sand and Gravel → K & S Sand and Gravel; 2019-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David  Stoltzfus et al → K & S Sand and Gravel; 2019-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Stoltzfus et al → K & S Sand and Gravel; 2019-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arly  Kinniburgh et al → K & S Sand and Gravel; 2019-04-22 to current/open; source msha-controller-operator-history