# Relationship history for MSHA mine 0301904

Current hierarchy: **Norma Jean  Hill; Sam O  Ross → Arkansas Sand Company → Arkansas Sand Company**

- 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:** Arkmo Sand & Gravel → Arkansas Sand Company; 2004-10-13 to 2009-09-08; source msha-controller-operator-history
- **controller_controls_mine:** Sam O  Ross  et al → Arkansas Sand Company; 2004-10-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sam O  Ross  et al → Arkmo Sand & Gravel; 2004-10-13 to 2009-09-08; source msha-controller-operator-history
- **controller_controls_operator:** Bob  Pinson  et al → Arkmo Sand & Gravel; 2004-10-13 to 2009-09-08; source msha-controller-operator-history
- **controller_controls_operator:** James  Starkey  et al → Arkmo Sand & Gravel; 2004-10-13 to 2009-09-08; source msha-controller-operator-history
- **operator_operates_mine:** Arkansas Sand Company → Arkansas Sand Company; 2009-09-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Norma Jean  Hill  et al → Arkansas Sand Company; 2009-09-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norma Jean  Hill  et al → Arkansas Sand Company; 2009-09-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sam O  Ross  et al → Arkansas Sand Company; 2009-09-09 to current/open; source msha-controller-operator-history