Early voting in the August 8 primaries begins Saturday. Here are the Denver locations:
Montbello Rec. Center, 15555 E. 53rd Ave.
Montclair Rec. Center, 729 Ulster Way
District 3 Police Station, 1625 S. University Blvd.
Athmar Rec. Center, 2680 W. Mexico Ave.
Scheitler Rec. Center, 5031 W. 46th Ave.
Wellington Webb Building, 201 W. Colfax Ave.
Here is a brochure (pdf) listing all of the early voting locations.
Colorado Confidential has more details.