# Relationship history for MSHA mine 2103855

Current hierarchy: **Ivie  Popplewell; Thomas J  Rowekamp → I.T. Sand LLC → Nisbit Mine**

- 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:** I.T. Sand LLC → Nisbit Mine; 2015-05-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas J  Rowekamp et al → Nisbit Mine; 2015-05-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas J  Rowekamp et al → I.T. Sand LLC; 2015-05-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ivie  Popplewell et al → I.T. Sand LLC; 2015-05-26 to current/open; source msha-controller-operator-history