# Relationship history for MSHA mine 1800708

Current hierarchy: **Wm Alan  Boehm; Wm Ryan  Boehm; Joseph A  Boehm → Chesterfield FARMS LLC → Tuckahoe Sand**

- 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:** Shufelt Sand & Gravel → Tuckahoe Sand; 1984-08-01 to 2019-04-02; source msha-controller-operator-history
- **controller_controls_mine:** Johnson T  Shufelt → Tuckahoe Sand; 1984-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson T  Shufelt → Shufelt Sand & Gravel; 1984-08-01 to 2019-04-02; source msha-controller-operator-history
- **operator_operates_mine:** Chesterfield FARMS LLC → Tuckahoe Sand; 2019-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Wm Ryan  Boehm et al → Tuckahoe Sand; 2019-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wm Ryan  Boehm et al → Chesterfield FARMS LLC; 2019-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph A  Boehm et al → Chesterfield FARMS LLC; 2019-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wm Alan  Boehm et al → Chesterfield FARMS LLC; 2019-04-03 to current/open; source msha-controller-operator-history