# Relationship history for MSHA mine 0103238

Current hierarchy: **Earl D  Kerr → Kerr's Redi Mix Inc → Sand Mountain Materials**

- 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:** Sand Mountain Sand LLC → Sand Mountain Materials; 2002-03-05 to 2007-12-13; source msha-controller-operator-history
- **controller_controls_mine:** Ledford  Cook → Sand Mountain Materials; 2002-03-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ledford  Cook → Sand Mountain Sand LLC; 2002-03-05 to 2007-12-13; source msha-controller-operator-history
- **operator_operates_mine:** Kerr's Redi Mix Inc → Sand Mountain Materials; 2007-12-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Earl D  Kerr → Sand Mountain Materials; 2007-12-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Earl D  Kerr → Kerr's Redi Mix Inc; 2007-12-14 to current/open; source msha-controller-operator-history