# Relationship history for MSHA mine 0200536

Current hierarchy: **Honeywell → UOP LLC → BOWIE CHABAZITE OPERATIONS**

- 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:** Cholla Construction → BOWIE CHABAZITE OPERATIONS; 1950-01-01 to 1980-04-28; source msha-controller-operator-history
- **controller_controls_mine:** Grusendorf M C → BOWIE CHABAZITE OPERATIONS; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Grusendorf M C → Cholla Construction; 1950-01-01 to 1980-04-28; source msha-controller-operator-history
- **operator_operates_mine:** Union Carbide Molecular Sieves → BOWIE CHABAZITE OPERATIONS; 1980-04-29 to 1988-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Union Carbide Corp → BOWIE CHABAZITE OPERATIONS; 1980-04-29 to 1988-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Union Carbide Corp → Union Carbide Molecular Sieves; 1980-04-29 to 1988-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Uop → BOWIE CHABAZITE OPERATIONS; 1989-01-01 to 2001-05-21; source msha-controller-operator-history
- **controller_controls_mine:** Union Carbide Corp & Allied-Signal Inc → BOWIE CHABAZITE OPERATIONS; 1989-01-01 to 2001-05-21; source msha-controller-operator-history
- **controller_controls_operator:** Union Carbide Corp & Allied-Signal Inc → Uop; 1989-01-01 to 2001-05-21; source msha-controller-operator-history
- **operator_operates_mine:** UOP LLC → BOWIE CHABAZITE OPERATIONS; 2001-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Honeywell → BOWIE CHABAZITE OPERATIONS; 2001-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Honeywell → UOP LLC; 2001-05-22 to current/open; source msha-controller-operator-history