# Relationship history for MSHA mine 0405742

Current hierarchy: **Ted E  Contri; Ted E  Contri → Mercer-Fraser Company → Bridgeville Quarry**

- 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:** Bott William F → Bridgeville Quarry; 1950-01-01 to 2002-01-15; source msha-controller-operator-history
- **controller_controls_mine:** Ted E  Contri  et al → Bridgeville Quarry; 2002-01-16 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ladd and Associates → Bridgeville Quarry; 2007-12-19 to 2009-07-07; source msha-controller-operator-history
- **controller_controls_mine:** Eric R  Ladd et al → Bridgeville Quarry; 2007-12-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eric R  Ladd et al → Ladd and Associates; 2007-12-19 to 2009-07-07; source msha-controller-operator-history
- **operator_operates_mine:** Wendt Construction Co Inc → Bridgeville Quarry; 2009-07-08 to 2011-03-27; source msha-controller-operator-history
- **controller_controls_mine:** Dennis  Wendt → Bridgeville Quarry; 2009-07-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis  Wendt → Wendt Construction Co Inc; 2009-07-08 to 2011-03-27; source msha-controller-operator-history
- **operator_operates_mine:** Mercer-Fraser Company → Bridgeville Quarry; 2011-03-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ted E  Contri  et al → Mercer-Fraser Company; 2011-03-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bott William F → Mercer-Fraser Company; 2011-03-28 to 2002-01-15; source msha-controller-operator-history