# Relationship history for MSHA mine 4103115

Current hierarchy: **Newpark Resources Inc → Excalibar Minerals Inc → EXCALIBAR MINERALS 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:** Uni Minerals Corp → EXCALIBAR MINERALS INC; 1980-11-01 to 1989-05-02; source msha-controller-operator-history
- **controller_controls_mine:** Unibar Corp → EXCALIBAR MINERALS INC; 1980-11-01 to 1989-05-02; source msha-controller-operator-history
- **controller_controls_operator:** Unibar Corp → Uni Minerals Corp; 1980-11-01 to 1989-05-02; source msha-controller-operator-history
- **operator_operates_mine:** Global United Industries Inc → EXCALIBAR MINERALS INC; 1989-05-03 to 1991-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Woods Eddie → EXCALIBAR MINERALS INC; 1989-05-03 to 1991-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Woods Eddie → Global United Industries Inc; 1989-05-03 to 1991-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Excalibar Minerals Inc → EXCALIBAR MINERALS INC; 1991-07-01 to 1997-08-27; source msha-controller-operator-history
- **controller_controls_mine:** T E  Eisenman → EXCALIBAR MINERALS INC; 1991-07-01 to 1997-09-17; source msha-controller-operator-history
- **controller_controls_operator:** T E  Eisenman → Excalibar Minerals Inc; 1991-07-01 to 1997-08-27; source msha-controller-operator-history
- **operator_operates_mine:** Excalibar Minerals Inc → EXCALIBAR MINERALS INC; 1997-08-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Newpark Resources Inc → EXCALIBAR MINERALS INC; 1997-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Newpark Resources Inc → Excalibar Minerals Inc; 1997-09-18 to current/open; source msha-controller-operator-history