# Relationship history for MSHA mine 3401970

Current hierarchy: **Joseph  Qualls; Michael  Qualls → Solid Rock Stone, Inc. → CALHOUN 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

- **operator_operates_mine:** Solid Rock Stone, Inc. → CALHOUN PIT; 2005-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Michael  Qualls et al → CALHOUN PIT; 2005-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Qualls et al → Solid Rock Stone, Inc.; 2005-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph  Qualls et al → Solid Rock Stone, Inc.; 2005-07-21 to current/open; source msha-controller-operator-history