# Relationship history for MSHA mine 2501174

Current hierarchy: **Mark J  Chrisman → Mark Chrisman Trucking Inc. → Screening Plant**

- 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:** Sample Brothers Inc → Screening Plant; 1997-07-01 to 2003-09-16; source msha-controller-operator-history
- **controller_controls_mine:** Ray  Sample → Screening Plant; 1997-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ray  Sample → Sample Brothers Inc; 1997-07-01 to 2003-09-16; source msha-controller-operator-history
- **operator_operates_mine:** Mark Chrisman Trucking → Screening Plant; 2003-09-17 to 2007-12-04; source msha-controller-operator-history
- **controller_controls_mine:** Mark J  Chrisman → Screening Plant; 2003-09-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark J  Chrisman → Mark Chrisman Trucking; 2003-09-17 to 2007-12-04; source msha-controller-operator-history
- **operator_operates_mine:** Mark Chrisman Trucking Inc → Screening Plant; 2007-12-05 to 2008-02-24; source msha-controller-operator-history
- **controller_controls_mine:** Mark J  Chrisman → Screening Plant; 2007-12-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark J  Chrisman → Mark Chrisman Trucking Inc; 2007-12-05 to 2008-02-24; source msha-controller-operator-history
- **operator_operates_mine:** Heggem Construction Inc → Screening Plant; 2008-02-25 to 2012-05-11; source msha-controller-operator-history
- **controller_controls_mine:** Justin  Heggem → Screening Plant; 2008-02-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Justin  Heggem → Heggem Construction Inc; 2008-02-25 to 2012-05-11; source msha-controller-operator-history
- **operator_operates_mine:** Mark Chrisman Trucking Inc. → Screening Plant; 2012-05-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark J  Chrisman → Mark Chrisman Trucking Inc.; 2012-05-12 to current/open; source msha-controller-operator-history