# Relationship history for MSHA mine 0800901

Current hierarchy: **Glades Rock & Sand Inc → Glades Rock & Sand Inc → Hollywood Plant**

- 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:** Glades Rock & Sand Inc → Hollywood Plant; 1978-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Glades Rock & Sand Inc → Hollywood Plant; 1978-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Glades Rock & Sand Inc → Glades Rock & Sand Inc; 1978-10-01 to current/open; source msha-controller-operator-history