# Relationship history for MSHA mine 2700335

Current hierarchy: **Barnstead Sand and Gravel → NorthEast Earth Mechanics, Inc. → Sam Clark Rd./Welch Rd. Pit**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Barnstead Sand and Gravel → Sam Clark Rd./Welch Rd. Pit; 1998-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Northeast Earth Mechanics Inc → Sam Clark Rd./Welch Rd. Pit; 1998-12-01 to 2005-06-21; source msha-controller-operator-history
- **controller_controls_mine:** James N  Locke II → Sam Clark Rd./Welch Rd. Pit; 1998-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James N  Locke II → Northeast Earth Mechanics Inc; 1998-12-01 to 2005-06-21; source msha-controller-operator-history
- **operator_operates_mine:** NorthEast Earth Mechanics, Inc. → Sam Clark Rd./Welch Rd. Pit; 2005-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barnstead Sand and Gravel → NorthEast Earth Mechanics, Inc.; 2005-06-22 to current/open; source msha-controller-operator-history