# Relationship history for MSHA mine 1900281

Current hierarchy: **Fafard H A & Sons Construction Inc → Ashland Sand & Stone Company → Ashland Sand & Stone**

- 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:** Ashland Sand & Concrete Company Inc → Ashland Sand & Stone; 1950-01-01 to 1985-06-26; source msha-controller-operator-history
- **controller_controls_mine:** Janock Irving W → Ashland Sand & Stone; 1950-01-01 to 1985-06-26; source msha-controller-operator-history
- **controller_controls_operator:** Janock Irving W → Ashland Sand & Concrete Company Inc; 1950-01-01 to 1985-06-26; source msha-controller-operator-history
- **operator_operates_mine:** Rosenfeld Concrete Corp → Ashland Sand & Stone; 1985-06-27 to 1986-06-05; source msha-controller-operator-history
- **controller_controls_mine:** Boston Sand & Gravel Company → Ashland Sand & Stone; 1985-06-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Boston Sand & Gravel Company → Rosenfeld Concrete Corp; 1985-06-27 to 1986-06-05; source msha-controller-operator-history
- **operator_operates_mine:** Ashland Sand & Stone Company → Ashland Sand & Stone; 1986-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Fafard H A & Sons Construction Inc → Ashland Sand & Stone; 1986-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fafard H A & Sons Construction Inc → Ashland Sand & Stone Company; 1986-06-06 to current/open; source msha-controller-operator-history