# Relationship history for MSHA mine 3400699

Current hierarchy: **Joel  Stringfellow; Curtis  Stringfellow → Stringfellow & Sons Inc → Hartshorne Quarry 1**

- 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

- **controller_controls_mine:** Curtis  Stringfellow et al → Hartshorne Quarry 1; 1989-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Stringfellow & Sons Inc → Hartshorne Quarry 1; 1993-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Curtis  Stringfellow et al → Stringfellow & Sons Inc; 1993-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joel  Stringfellow et al → Stringfellow & Sons Inc; 1993-05-01 to current/open; source msha-controller-operator-history