# Relationship history for MSHA mine 4700886

Current hierarchy: **Holcim Ltd → Lafarge North America Great Lakes Division → Dousman Pit Yard 11**

- 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:** Tews Company → Dousman Pit Yard 11; 1950-01-01 to 1998-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Robert G  Tews et al → Dousman Pit Yard 11; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert G  Tews et al → Tews Company; 1950-01-01 to 1998-06-30; source msha-controller-operator-history
- **controller_controls_operator:** William L  Tews et al → Tews Company; 1950-01-01 to 1998-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge-Wisconsin Division → Dousman Pit Yard 11; 1998-07-01 to 2002-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Dousman Pit Yard 11; 1998-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge-Wisconsin Division; 1998-07-01 to 2002-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Dousman Pit Yard 11; 2001-07-12 to 2015-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge North America → Dousman Pit Yard 11; 2002-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge North America; 2002-04-01 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Dousman Pit Yard 11; 2015-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Lafarge North America; 2015-07-10 to current/open; source msha-controller-operator-history