# Relationship history for MSHA mine 2103479

Current hierarchy: **Janet  Hammerlund → TNT Construction Group, LLC → Harris Pit-Portable Crusher**

- 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:** Hammerlund Construction Inc → Harris Pit-Portable Crusher; 2005-04-12 to 2023-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Thomas E  Hammerlund → Harris Pit-Portable Crusher; 2005-04-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas E  Hammerlund → Hammerlund Construction Inc; 2005-04-12 to 2023-03-31; source msha-controller-operator-history
- **operator_operates_mine:** TNT Construction Group, LLC → Harris Pit-Portable Crusher; 2023-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Janet  Hammerlund → Harris Pit-Portable Crusher; 2023-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Janet  Hammerlund → TNT Construction Group, LLC; 2023-04-01 to current/open; source msha-controller-operator-history