# Relationship history for MSHA mine 0901201

Current hierarchy: **Mark E  Simmons; Melissa F  Simmons → South River Sand → South River Sand**

- 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:** South River Sand → South River Sand; 2010-03-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Melissa F  Simmons et al → South River Sand; 2010-03-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Melissa F  Simmons et al → South River Sand; 2010-03-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark E  Simmons et al → South River Sand; 2010-03-18 to current/open; source msha-controller-operator-history