# Relationship history for MSHA mine 3002234

Current hierarchy: **Bruce M.  Buyers; Michael J  Fronckowiak → Java Materials, Inc. → Java Materials**

- 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:** Han-Kin Gravel Inc → Java Materials; 1950-01-01 to 1979-05-02; source msha-controller-operator-history
- **controller_controls_mine:** Handley John → Java Materials; 1950-01-01 to 1979-05-02; source msha-controller-operator-history
- **controller_controls_operator:** Handley John → Han-Kin Gravel Inc; 1950-01-01 to 1979-05-02; source msha-controller-operator-history
- **operator_operates_mine:** Centerline Gravel Products Inc → Java Materials; 1979-05-03 to 2006-06-07; source msha-controller-operator-history
- **controller_controls_mine:** Dupre Joseph → Java Materials; 1979-05-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dupre Joseph → Centerline Gravel Products Inc; 1979-05-03 to 2006-06-07; source msha-controller-operator-history
- **operator_operates_mine:** Java Materials, Inc. → Java Materials; 2006-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Michael J  Fronckowiak et al → Java Materials; 2006-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael J  Fronckowiak et al → Java Materials, Inc.; 2006-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bruce M.  Buyers et al → Java Materials, Inc.; 2006-06-08 to current/open; source msha-controller-operator-history