# Relationship history for MSHA mine 0801248

Current hierarchy: **Joseph H  Anderson → Anderson Columbia Company Inc → Imperial Rock 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Anderson Columbia Company Inc → Imperial Rock Mine; 1997-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Joseph H  Anderson et al → Imperial Rock Mine; 1997-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph H  Anderson et al → Anderson Columbia Company Inc; 1997-06-01 to current/open; source msha-controller-operator-history