# Relationship history for MSHA mine 5001790

Current hierarchy: **Curtis P  Dufendach; Brian T  Johnson → Delta Industrial Services Inc → Carns Gravel 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

- **operator_operates_mine:** Carns General Contractors Inc. → Carns Gravel Pit; 2004-04-02 to 2006-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Ed  Carns → Carns Gravel Pit; 2004-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ed  Carns → Carns General Contractors Inc.; 2004-04-02 to 2006-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Delta Industrial Services Inc → Carns Gravel Pit; 2006-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Michael L  Crouch  et al → Carns Gravel Pit; 2006-03-01 to 2017-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Michael L  Crouch  et al → Delta Industrial Services Inc; 2006-03-01 to 2017-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Jon W  Dufendach  et al → Delta Industrial Services Inc; 2006-03-01 to 2017-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Curtis P  Dufendach et al → Carns Gravel Pit; 2017-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Curtis P  Dufendach et al → Delta Industrial Services Inc; 2017-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brian T  Johnson et al → Delta Industrial Services Inc; 2017-02-01 to current/open; source msha-controller-operator-history