The Republican vice presidential candidate spoke at a rally Monday at Johnson's Corner north of Denver.
Ryan's visit comes after 1.6 million Coloradans cast their vote early, including 35 percent from Democrats and 37 percent from Republicans.
President Barack Obama spoke before 20,000 supporters at a rally Sunday in Aurora in his final stop in Colorado before Election Day.
He said Aurora knows about tragedy after this summer's shooting at a theater left 12 people dead and 58 injured.
He accused Mitt Romney of trying to hide his positions and pretending to be the candidate of change. Romney capped off his Colorado campaign with a rally in Englewood Saturday night.
(Copyright 2012 by The Associated Press. All Rights Reserved.)