# Relationship history for MSHA mine 0301960

Current hierarchy: **James J  Johnston → Quality Rock, Inc. → Portable Plant #1**

- 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:** James J  Johnston et al → Portable Plant #1; 2004-03-10 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** JLC Quarries LLC → Portable Plant #1; 2007-10-12 to 2009-03-10; source msha-controller-operator-history
- **controller_controls_mine:** James J  Johnston et al → Portable Plant #1; 2007-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James J  Johnston et al → JLC Quarries LLC; 2007-10-12 to 2009-03-10; source msha-controller-operator-history
- **operator_operates_mine:** Quality Rock, Inc. → Portable Plant #1; 2009-03-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James J  Johnston et al → Quality Rock, Inc.; 2009-03-11 to current/open; source msha-controller-operator-history