Genomic data and annotations are rapidly accumulating in databases such as the UCSC Genome Browser, NCBI, and Ensembl. Given the massive scale of these genomic databases, it is important to be able to easily retrieve known data and annotations of a specified genomic locus. For example, for a newly identified cis-regulatory element bound by a transcription factor, questions that immediately come to mind include whether the element is near a transcriptional start site and, if so, the name of the corresponding gene, and whether the histones or DNA at the locus are modified. The UCSC Genome Browser organizes data and annotations (called tracks) around the reference sequences or draft assemblies of many eukaryotic genomes and presents them using a powerful web-based graphical interface. This protocol describes how to use the UCSC Genome Browser to visualize selected tracks at specified genomic regions, download the data and annotations for further analysis, and retrieve multiple sequence alignments and their conservation scores.