# Relationship history for MSHA mine 4201664

Current hierarchy: **Davidson Howard → Dav-Tex Corp → Poor Boy**

- 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:** B & B Mining Company → Poor Boy; 1980-05-01 to 1981-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Barnes Robert J → Poor Boy; 1980-05-01 to 1981-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Barnes Robert J → B & B Mining Company; 1980-05-01 to 1981-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Diatex Inc → Poor Boy; 1981-04-01 to 1982-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Diamin Holdings Ltd → Poor Boy; 1981-04-01 to 1982-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Diamin Holdings Ltd → Diatex Inc; 1981-04-01 to 1982-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Engle Industries Inc → Poor Boy; 1982-04-01 to 1982-06-22; source msha-controller-operator-history
- **controller_controls_mine:** Swope James S → Poor Boy; 1982-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Swope James S → Engle Industries Inc; 1982-04-01 to 1982-06-22; source msha-controller-operator-history
- **operator_operates_mine:** Dav-Tex Corp → Poor Boy; 1982-06-23 to 1983-01-17; source msha-controller-operator-history
- **controller_controls_mine:** Davidson Howard → Poor Boy; 1982-06-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Davidson Howard → Dav-Tex Corp; 1982-06-23 to 1983-01-17; source msha-controller-operator-history
- **operator_operates_mine:** Bob Barnes Mining → Poor Boy; 1983-01-18 to 1985-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Barnes Robert J → Poor Boy; 1983-01-18 to 1985-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Barnes Robert J → Bob Barnes Mining; 1983-01-18 to 1985-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Dav-Tex Corp → Poor Boy; 1985-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Davidson Howard → Dav-Tex Corp; 1985-03-01 to current/open; source msha-controller-operator-history