# Relationship history for MSHA mine 4606836

Current hierarchy: **Pierson David W → Pierson Lumber Company → #2 Mine**

- 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:** Avoca Inc → #2 Mine; 1984-08-01 to 1986-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Guidi Gary → #2 Mine; 1984-08-01 to 1986-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Guidi Gary → Avoca Inc; 1984-08-01 to 1986-09-14; source msha-controller-operator-history
- **operator_operates_mine:** Pierson Lumber Company → #2 Mine; 1986-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pierson David W → #2 Mine; 1986-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pierson David W → Pierson Lumber Company; 1986-09-15 to current/open; source msha-controller-operator-history