# Relationship history for MSHA mine 3502501

Current hierarchy: **CROMOS Mining & Crushing LLC; Kristofer T  Hornsby → West Coast Mining & Crushing Inc. → West Coast Mining & Crushing Portable**

- 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:** Nesko Rock, Inc. → West Coast Mining & Crushing Portable; 1950-01-01 to 2004-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Mike L Kowalski → West Coast Mining & Crushing Portable; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mike L Kowalski → Nesko Rock, Inc.; 1950-01-01 to 2004-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Nesko Rock → West Coast Mining & Crushing Portable; 2004-07-01 to 2011-02-20; source msha-controller-operator-history
- **controller_controls_mine:** David Alan  Hornsby → West Coast Mining & Crushing Portable; 2004-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David Alan  Hornsby → Nesko Rock; 2004-07-01 to 2011-02-20; source msha-controller-operator-history
- **operator_operates_mine:** West Coast Mining & Crushing Inc. → West Coast Mining & Crushing Portable; 2011-02-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CROMOS Mining & Crushing LLC et al → West Coast Mining & Crushing Portable; 2011-02-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CROMOS Mining & Crushing LLC et al → West Coast Mining & Crushing Inc.; 2011-02-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kristofer T  Hornsby et al → West Coast Mining & Crushing Inc.; 2011-02-21 to current/open; source msha-controller-operator-history