# Relationship history for MSHA mine 0400104

Current hierarchy: **Spreckels Industries Inc → Limestone Products Company Inc → Spreckels Limestone & Aggregate Products**

- 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:** El Dorado Limestone Company → Spreckels Limestone & Aggregate Products; 1950-01-01 to 1986-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Gallo Glass Company → Spreckels Limestone & Aggregate Products; 1950-01-01 to 1986-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Gallo Glass Company → El Dorado Limestone Company; 1950-01-01 to 1986-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Amstar Limestone Products → Spreckels Limestone & Aggregate Products; 1986-11-14 to 1988-07-11; source msha-controller-operator-history
- **controller_controls_mine:** Amstar Corp → Spreckels Limestone & Aggregate Products; 1986-11-14 to 1988-07-11; source msha-controller-operator-history
- **controller_controls_operator:** Amstar Corp → Amstar Limestone Products; 1986-11-14 to 1988-07-11; source msha-controller-operator-history
- **operator_operates_mine:** Limestone Products Company Inc → Spreckels Limestone & Aggregate Products; 1988-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Spreckels Industries Inc → Spreckels Limestone & Aggregate Products; 1988-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Spreckels Industries Inc → Limestone Products Company Inc; 1988-07-12 to current/open; source msha-controller-operator-history