Since OMIM has only allowed Data queries within individual chromosomes, no download files are available from the Genome Browser. Full genome datasets can be downloaded directly from the OMIM Downloads page. All genome-wide downloads are freely available from OMIM after registration.
If you need the OMIM data in exactly the format of the UCSC Genome Browser, for example if you are running a UCSC Genome Browser local installation (a partial "mirror"), please create a user account on omim.org and contact OMIM via https://omim.org/contact. Send them your OMIM -account name and request access to the UCSC Genome Browser 'entitlement'. They will +account name and request access to the UCSC Genome Browser "entitlement". They will then grant you access to a MySQL/MariaDB data dump that contains all UCSC Genome Browser OMIM tables.
UCSC offers queries within chromosomes from Table Browser that include a variety of filtering options and cross-referencing other datasets using our Data Integrator tool. UCSC also has an API that can be used to retrieve data in JSON format from a particular chromosome range.
Please refer to our searchable mailing list archives for more questions and example queries, or our Data Access FAQ