# Relationship history for MSHA mine 2000789

Current hierarchy: **Tyler  Austin; Robert  Haack → North Chester Holdings LLC → Ravenna Gravel**

- 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:** Muskegon Gravel & Redi-Mix → Ravenna Gravel; 1950-01-01 to 1986-09-09; source msha-controller-operator-history
- **controller_controls_mine:** Kenneth L Greene → Ravenna Gravel; 1950-01-01 to 1986-09-09; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth L Greene → Muskegon Gravel & Redi-Mix; 1950-01-01 to 1986-09-09; source msha-controller-operator-history
- **operator_operates_mine:** Ravenna Gravel → Ravenna Gravel; 1986-09-10 to 1989-05-30; source msha-controller-operator-history
- **controller_controls_mine:** Andrew  Sorensen et al → Ravenna Gravel; 1986-09-10 to 1989-05-30; source msha-controller-operator-history
- **controller_controls_operator:** Andrew  Sorensen et al → Ravenna Gravel; 1986-09-10 to 1989-05-30; source msha-controller-operator-history
- **operator_operates_mine:** Ravenna Gravel → Ravenna Gravel; 1989-05-31 to 2026-07-23; source msha-controller-operator-history
- **controller_controls_mine:** Barry J  Glovick → Ravenna Gravel; 1989-05-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barry J  Glovick → Ravenna Gravel; 1989-05-31 to 2026-07-23; source msha-controller-operator-history
- **operator_operates_mine:** North Chester Holdings LLC → Ravenna Gravel; 2026-07-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Haack et al → Ravenna Gravel; 2026-07-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Haack et al → North Chester Holdings LLC; 2026-07-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tyler  Austin et al → North Chester Holdings LLC; 2026-07-24 to current/open; source msha-controller-operator-history