# Relationship history for MSHA mine 2700062

Current hierarchy: **Boston Sand & Gravel Company → MANCHESTER SAND GRAVEL & CEMENT COMPANY INC → HOOKSETT GP #1**

- 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:** Manchester Sand-Gravel & Cement Company Inc → HOOKSETT GP #1; 1950-01-01 to 1979-07-24; source msha-controller-operator-history
- **controller_controls_mine:** J G MacLellan Concrete Company Inc → HOOKSETT GP #1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** J G MacLellan Concrete Company Inc → Manchester Sand-Gravel & Cement Company Inc; 1950-01-01 to 1979-07-24; source msha-controller-operator-history
- **controller_controls_mine:** Boston Sand & Gravel Company → HOOKSETT GP #1; 1979-07-10 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Manchester Sand Gravel & Cement Company Inc → HOOKSETT GP #1; 1979-07-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Boston Sand & Gravel Company → Manchester Sand Gravel & Cement Company Inc; 1979-07-25 to current/open; source msha-controller-operator-history