# Relationship history for MSHA mine 3607055

Current hierarchy: **Huston Edwin P → D & E Construction Company → Roxbury Strip**

- 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:** D & E Construction Company → Roxbury Strip; 1980-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Huston Edwin P → Roxbury Strip; 1980-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Huston Edwin P → D & E Construction Company; 1980-11-01 to current/open; source msha-controller-operator-history