# Relationship history for MSHA mine 3301437

Current hierarchy: **Jessie L  Schmeltz → Precision Aggregates I → PRECISION AGGREGATES I**

- 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:** Amert Gravel Company → PRECISION AGGREGATES I; 1950-01-01 to 1988-03-16; source msha-controller-operator-history
- **controller_controls_mine:** J E  Amert  et al → PRECISION AGGREGATES I; 1950-01-01 to 1988-03-16; source msha-controller-operator-history
- **controller_controls_operator:** J E  Amert  et al → Amert Gravel Company; 1950-01-01 to 1988-03-16; source msha-controller-operator-history
- **operator_operates_mine:** Precision Aggregates I → PRECISION AGGREGATES I; 1988-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Randolph  Schmeltz Sr → PRECISION AGGREGATES I; 1988-03-17 to 2021-04-23; source msha-controller-operator-history
- **controller_controls_operator:** Randolph  Schmeltz Sr → Precision Aggregates I; 1988-03-17 to 2021-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Jessie L  Schmeltz → PRECISION AGGREGATES I; 2021-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jessie L  Schmeltz → Precision Aggregates I; 2021-04-24 to current/open; source msha-controller-operator-history