# Relationship history for MSHA mine 2000692

Current hierarchy: **Andrew  Dykema → Coit Avenue Gravel Company → Plant #1**

- 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:** Coit Avenue Gravel Company Inc → Plant #1; 1950-01-01 to 1991-06-26; source msha-controller-operator-history
- **controller_controls_mine:** Joseph E  Thome  et al → Plant #1; 1950-01-01 to 1991-10-03; source msha-controller-operator-history
- **controller_controls_operator:** Joseph E  Thome  et al → Coit Avenue Gravel Company Inc; 1950-01-01 to 1991-06-26; source msha-controller-operator-history
- **operator_operates_mine:** Coit Avenue Gravel Company → Plant #1; 1991-06-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Andrew  Dykema  et al → Plant #1; 1991-06-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Andrew  Dykema  et al → Coit Avenue Gravel Company; 1991-06-27 to current/open; source msha-controller-operator-history