# Relationship history for MSHA mine 3600682

Current hierarchy: **Maynard J.  Frantz → FRANTZ BROS INC → KUNKLETOWN CLAY PIT**

- 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

- **controller_controls_mine:** Heidelberg Materials AG → KUNKLETOWN CLAY PIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lehigh Portland Cement Company → KUNKLETOWN CLAY PIT; 1980-12-01 to 2002-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Lehigh Portland Cement Company; 1980-12-01 to 2002-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → KUNKLETOWN CLAY PIT; 2000-07-21 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lehigh Cement Co. → KUNKLETOWN CLAY PIT; 2002-02-01 to 2006-05-09; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Lehigh Cement Co.; 2002-02-01 to 2006-05-09; source msha-controller-operator-history
- **operator_operates_mine:** Frantz Bros Inc → KUNKLETOWN CLAY PIT; 2006-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Maynard J.  Frantz et al → KUNKLETOWN CLAY PIT; 2006-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Maynard J.  Frantz et al → Frantz Bros Inc; 2006-05-10 to current/open; source msha-controller-operator-history