# Relationship history for MSHA mine 3400550

Current hierarchy: **Joseph L  Parker Jr → Anchor Stone Company → Delaware Sand Plant**

- 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:** East Tulsa Sand Company → Delaware Sand Plant; 1950-01-01 to 1985-06-14; source msha-controller-operator-history
- **controller_controls_mine:** James J  Aud → Delaware Sand Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James J  Aud → East Tulsa Sand Company; 1950-01-01 to 1985-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Joseph L  Parker Jr → Delaware Sand Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Waits Enterprises Inc → Delaware Sand Plant; 1985-06-15 to 1989-01-02; source msha-controller-operator-history
- **controller_controls_mine:** John L  Waits → Delaware Sand Plant; 1985-06-15 to 1989-01-02; source msha-controller-operator-history
- **controller_controls_operator:** John L  Waits → Waits Enterprises Inc; 1985-06-15 to 1989-01-02; source msha-controller-operator-history
- **operator_operates_mine:** Newkirk Sand Company → Delaware Sand Plant; 1989-01-03 to 1992-02-14; source msha-controller-operator-history
- **controller_controls_mine:** Paul E Newkirk → Delaware Sand Plant; 1989-01-03 to 1992-02-14; source msha-controller-operator-history
- **controller_controls_operator:** Paul E Newkirk → Newkirk Sand Company; 1989-01-03 to 1992-02-14; source msha-controller-operator-history
- **operator_operates_mine:** Anchor Stone Company → Delaware Sand Plant; 1992-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph L  Parker Jr → Anchor Stone Company; 1992-02-15 to current/open; source msha-controller-operator-history