# Relationship history for MSHA mine 4500581

Current hierarchy: **Richard  Hurworth → DelHur Industries, Inc. → Blake Pit**

- 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

- **controller_controls_mine:** Samuel G  Hurworth → Blake Pit; 1950-01-01 to 2025-09-16; source msha-controller-operator-history
- **operator_operates_mine:** Blake Sand & Gravel Inc → Blake Pit; 1950-01-01 to 2002-03-31; source msha-controller-operator-history
- **controller_controls_mine:** David A  Blake → Blake Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David A  Blake → Blake Sand & Gravel Inc; 1950-01-01 to 2002-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Alex J  Hill et al → Blake Pit; 1977-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Fred Hill Materials Inc → Blake Pit; 2002-04-01 to 2010-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Alex J  Hill et al → Fred Hill Materials Inc; 2002-04-01 to 2010-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Adam  Hill et al → Fred Hill Materials Inc; 2002-04-01 to 2010-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Blake Sand & Gravel, Inc. → Blake Pit; 2010-05-01 to 2024-04-14; source msha-controller-operator-history
- **controller_controls_mine:** David A  Blake et al → Blake Pit; 2010-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David A  Blake et al → Blake Sand & Gravel, Inc.; 2010-05-01 to 2024-04-14; source msha-controller-operator-history
- **controller_controls_operator:** Casey L  Blake et al → Blake Sand & Gravel, Inc.; 2010-05-01 to 2024-04-14; source msha-controller-operator-history
- **operator_operates_mine:** DelHur Industries, Inc. → Blake Pit; 2024-04-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Samuel G  Hurworth → DelHur Industries, Inc.; 2024-04-15 to 2025-09-16; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Hurworth → Blake Pit; 2025-09-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Hurworth → DelHur Industries, Inc.; 2025-09-17 to current/open; source msha-controller-operator-history