# Relationship history for MSHA mine 0404165

Current hierarchy: **Quikrete Holdings Inc. → Monarch Mountain Minerals & Aggregates, LLC → Glass Mountain Pumice**

- 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:** Royal Sierra Industries → Glass Mountain Pumice; 1950-01-01 to 1978-05-17; source msha-controller-operator-history
- **controller_controls_mine:** Strombeck Carl & Chris Nicolos → Glass Mountain Pumice; 1950-01-01 to 1978-05-17; source msha-controller-operator-history
- **controller_controls_operator:** Strombeck Carl & Chris Nicolos → Royal Sierra Industries; 1950-01-01 to 1978-05-17; source msha-controller-operator-history
- **operator_operates_mine:** Glass Mountain Pumice Inc → Glass Mountain Pumice; 1978-05-18 to 2004-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Niilo M  Hyytinen → Glass Mountain Pumice; 1978-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Niilo M  Hyytinen → Glass Mountain Pumice Inc; 1978-05-18 to 2004-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Glass Mountain Pumice 2004 LLC → Glass Mountain Pumice; 2004-04-01 to 2011-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Pavestone General Inc et al → Glass Mountain Pumice; 2004-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pavestone General Inc et al → Glass Mountain Pumice 2004 LLC; 2004-04-01 to 2011-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Robert J Schelegel et al → Glass Mountain Pumice 2004 LLC; 2004-04-01 to 2011-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Monarch Mountain Minerals & Aggregates, LLC → Glass Mountain Pumice; 2012-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Quikrete Holdings Inc. → Glass Mountain Pumice; 2012-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Quikrete Holdings Inc. → Monarch Mountain Minerals & Aggregates, LLC; 2012-01-01 to current/open; source msha-controller-operator-history