# Relationship history for MSHA mine 3607658

Current hierarchy: **Shilling Calvin G → Cal Coal Corp → Brown 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:** Cal Coal Corp → Brown Mine; 1985-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shilling Calvin G → Brown Mine; 1985-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shilling Calvin G → Cal Coal Corp; 1985-01-01 to current/open; source msha-controller-operator-history