# Relationship history for MSHA mine 1900284

Current hierarchy: **Edgar W  Sykes → E. W. Sykes General Contractors Inc. → E.W. Sykes General Contractors 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** B L Frye Inc → E.W. Sykes General Contractors Inc.; 1950-01-01 to 1984-10-02; source msha-controller-operator-history
- **controller_controls_mine:** Bradley L  Frye → E.W. Sykes General Contractors Inc.; 1950-01-01 to 1984-10-02; source msha-controller-operator-history
- **controller_controls_operator:** Bradley L  Frye → B L Frye Inc; 1950-01-01 to 1984-10-02; source msha-controller-operator-history
- **operator_operates_mine:** E. W. Sykes General Contractors Inc. → E.W. Sykes General Contractors Inc.; 1984-10-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Edgar W  Sykes → E.W. Sykes General Contractors Inc.; 1984-10-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edgar W  Sykes → E. W. Sykes General Contractors Inc.; 1984-10-03 to current/open; source msha-controller-operator-history