# Relationship history for MSHA mine 3302556

Current hierarchy: **Karg Thomas R → Karg Sand & Gravel Company → Karg Sand & Gravel Company**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Karg Sand & Gravel Company → Karg Sand & Gravel Company; 1950-01-01 to 1988-09-19; source msha-controller-operator-history
- **controller_controls_mine:** Karg Richard G → Karg Sand & Gravel Company; 1950-01-01 to 1988-09-19; source msha-controller-operator-history
- **controller_controls_operator:** Karg Richard G → Karg Sand & Gravel Company; 1950-01-01 to 1988-09-19; source msha-controller-operator-history
- **operator_operates_mine:** Karg Sand & Gravel Company → Karg Sand & Gravel Company; 1988-09-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Karg Thomas R → Karg Sand & Gravel Company; 1988-09-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Karg Thomas R → Karg Sand & Gravel Company; 1988-09-20 to current/open; source msha-controller-operator-history