# Relationship history for MSHA mine 3100444

Current hierarchy: **James T  Haney → Concrete Supply Company → ELLIS FERRY DREDGE**

- 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:** Shelby Sand & Stone Inc → ELLIS FERRY DREDGE; 1950-01-01 to 1983-04-04; source msha-controller-operator-history
- **controller_controls_mine:** Robert Patrick  Spangler → ELLIS FERRY DREDGE; 1950-01-01 to 1983-04-04; source msha-controller-operator-history
- **controller_controls_operator:** Robert Patrick  Spangler → Shelby Sand & Stone Inc; 1950-01-01 to 1983-04-04; source msha-controller-operator-history
- **operator_operates_mine:** Concrete Supply Company → ELLIS FERRY DREDGE; 1983-04-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James T  Haney → ELLIS FERRY DREDGE; 1983-04-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James T  Haney → Concrete Supply Company; 1983-04-05 to current/open; source msha-controller-operator-history