To turn on the miRNA track for a desired genome in the UCSC Genome Browser:

1. Bring up a UCSC Genome Browser window
2. Select the desired organism. For example to select human, select clade->Vertebrate and genome->Humam. Click "submit".
3. Scroll down to the "Genes and Gene Prediction Tracks" section, many animal organisms have "miRNA" menu available; pull down this menu and select any option other than "hide". Click "refresh" at the bottom of the page.
4. To test whether the miRNA track has been turned on for human, click here, a graphical view of hsa-let-7a-1 should appear in the genome browser window.
5. Once you have visited the UCSC Browser and selected track settings, you don't need to change them again unless desired- these settings are saved (as "cookies" in your web browser).