# Relationship history for MSHA mine 3605037

Current hierarchy: **Great American Coal Company → Blue Coal Corp → Glen Lyon Breaker**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Great American Coal Company → Glen Lyon Breaker; 1974-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Blue Coal Corp → Glen Lyon Breaker; 1974-03-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Great American Coal Company → Blue Coal Corp; 1974-03-11 to current/open; source msha-controller-operator-history