# Relationship history for MSHA mine 2902212

Current hierarchy: **GMS Inc; David  Shoup → United Materials, LLP → Travelstead**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Constructors Inc (NM) → Travelstead; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Langford Tractor Work Llc → Travelstead; 2001-01-01 to 2004-04-08; source msha-controller-operator-history
- **controller_controls_mine:** Gynn  Langford et al → Travelstead; 2001-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gynn  Langford et al → Langford Tractor Work Llc; 2001-01-01 to 2004-04-08; source msha-controller-operator-history
- **controller_controls_operator:** Grant  Langford et al → Langford Tractor Work Llc; 2001-01-01 to 2004-04-08; source msha-controller-operator-history
- **operator_operates_mine:** Constructors Inc → Travelstead; 2004-04-09 to 2015-05-07; source msha-controller-operator-history
- **controller_controls_operator:** Constructors Inc (NM) → Constructors Inc; 2004-04-09 to 2015-05-07; source msha-controller-operator-history
- **operator_operates_mine:** United Materials, LLP → Travelstead; 2015-05-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David  Shoup et al → Travelstead; 2015-05-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Shoup et al → United Materials, LLP; 2015-05-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** GMS Inc et al → United Materials, LLP; 2015-05-08 to current/open; source msha-controller-operator-history