# Relationship history for MSHA mine 1002237

Current hierarchy: **Francis R  Biscan Jr; David  Barefoot → Tara Minerals Corporation → Ponderosa**

- 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:** Tara Minerals Corporation → Ponderosa; 2013-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David  Barefoot et al → Ponderosa; 2013-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Barefoot et al → Tara Minerals Corporation; 2013-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Francis R  Biscan Jr et al → Tara Minerals Corporation; 2013-07-31 to current/open; source msha-controller-operator-history