# Relationship history for MSHA mine 4801690

Current hierarchy: **Carl E  Spomer → Spomer Construction Co Inc → Hart Garland 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:** Spomer Construction Co Inc → Hart Garland Mine; 2006-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Carl E  Spomer → Hart Garland Mine; 2006-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carl E  Spomer → Spomer Construction Co Inc; 2006-02-01 to current/open; source msha-controller-operator-history