# Relationship history for MSHA mine 0600027

Current hierarchy: **Imerys S A; Norsk Mineral AS → Feldspar Corp → Middletown Mine & Mill (Or) Feldspar**

- 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:** Feldspar Corp → Middletown Mine & Mill (Or) Feldspar; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Zemex Corp → Middletown Mine & Mill (Or) Feldspar; 1950-01-01 to 2003-03-02; source msha-controller-operator-history
- **controller_controls_operator:** Zemex Corp → Feldspar Corp; 1950-01-01 to 2003-03-02; source msha-controller-operator-history
- **controller_controls_mine:** Cementos Pacasmayo SSA → Middletown Mine & Mill (Or) Feldspar; 2003-03-03 to 2007-09-04; source msha-controller-operator-history
- **controller_controls_operator:** Cementos Pacasmayo SSA → Feldspar Corp; 2003-03-03 to 2007-09-04; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Middletown Mine & Mill (Or) Feldspar; 2007-09-05 to 2011-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → Feldspar Corp; 2007-09-05 to 2011-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A  et al → Middletown Mine & Mill (Or) Feldspar; 2011-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A  et al → Feldspar Corp; 2011-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norsk Mineral AS  et al → Feldspar Corp; 2011-04-01 to current/open; source msha-controller-operator-history