# Relationship history for MSHA mine 0504435

Current hierarchy: **Daniel  Conrado; Kathryn  Conrado → Meeker Sand & Gravel Inc → WASH PLANT & PORTABLE SCREEN**

- 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:** Meeker Sand & Gravel Inc → WASH PLANT & PORTABLE SCREEN; 1990-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Joe P  Conrado → WASH PLANT & PORTABLE SCREEN; 1990-07-01 to 2015-06-14; source msha-controller-operator-history
- **controller_controls_operator:** Joe P  Conrado → Meeker Sand & Gravel Inc; 1990-07-01 to 2015-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Daniel  Conrado et al → WASH PLANT & PORTABLE SCREEN; 2015-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniel  Conrado et al → Meeker Sand & Gravel Inc; 2015-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kathryn  Conrado et al → Meeker Sand & Gravel Inc; 2015-06-15 to current/open; source msha-controller-operator-history