# Relationship history for MSHA mine 1700515

Current hierarchy: **Scott  Pickard → City Line Sand & Gravel → City Line Sand & Gravel**

- 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:** Franklin Sand & Gravel → City Line Sand & Gravel; 1980-05-01 to 2003-10-15; source msha-controller-operator-history
- **controller_controls_mine:** Debeck Ruth → City Line Sand & Gravel; 1980-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Debeck Ruth → Franklin Sand & Gravel; 1980-05-01 to 2003-10-15; source msha-controller-operator-history
- **operator_operates_mine:** City Line Sand & Gravel → City Line Sand & Gravel; 2003-10-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Scott  Pickard → City Line Sand & Gravel; 2003-10-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scott  Pickard → City Line Sand & Gravel; 2003-10-16 to current/open; source msha-controller-operator-history