# Relationship history for MSHA mine 3606526

Current hierarchy: **Avery Inc → Avery Coal Company Inc → Rockton Tipple**

- 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

- **controller_controls_mine:** Bav Liquidating Corp → Rockton Tipple; 1976-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Avery Coal Company Inc → Rockton Tipple; 1977-01-01 to 1982-04-19; source msha-controller-operator-history
- **controller_controls_operator:** Bav Liquidating Corp → Avery Coal Company Inc; 1977-01-01 to 1982-04-19; source msha-controller-operator-history
- **operator_operates_mine:** Avery Coal Company Inc → Rockton Tipple; 1982-04-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Avery Inc → Rockton Tipple; 1982-04-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Avery Inc → Avery Coal Company Inc; 1982-04-20 to current/open; source msha-controller-operator-history