# Relationship history for MSHA mine 1516221

Current hierarchy: **Big Flea Market Inc → Pioneer Production Corp → No 2 Surface**

- 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:** Pioneer Production Corp → No 2 Surface; 1987-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Big Flea Market Inc → No 2 Surface; 1987-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Big Flea Market Inc → Pioneer Production Corp; 1987-10-01 to current/open; source msha-controller-operator-history