# Relationship history for MSHA mine 3606961

Current hierarchy: **Blaine E  Forbes → Neshannock Sand & Gravel, Inc → Neshannock Sand & Gravel, Inc.**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Moon'S Sand & Gravel Inc → Neshannock Sand & Gravel, Inc.; 1980-05-01 to 1989-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Francis  Schaville et al → Neshannock Sand & Gravel, Inc.; 1980-05-01 to 1989-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Francis  Schaville et al → Moon'S Sand & Gravel Inc; 1980-05-01 to 1989-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Neshannock Sand & Gravel, Inc → Neshannock Sand & Gravel, Inc.; 1989-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Blaine E  Forbes et al → Neshannock Sand & Gravel, Inc.; 1989-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blaine E  Forbes et al → Neshannock Sand & Gravel, Inc; 1989-06-01 to current/open; source msha-controller-operator-history