Keller, 32, plans to spend the next few days in Franklin County and then will march 15 to 25 miles a day, popping in businesses, community forums and group meetings along the way.
"I figured this would be the best way to get out and meet people and hear what's on their mind," Keller, a Hamilton Township resident, said Thursday.
"It goes hand in hand with my pledge not to accept more than $100 from a single donor," he said.
He hopes he will make it through all 14 counties in the district prior to the primary election. He will chronicle his trip on his Web site, www.davekellerforcongress.com.
His wife, Rebecca, and friends and family will catch up with him to provide changes of clothes and food.
Keller said he plans to poke his head in businesses he passes, and he expects that as word of his journey gets out, people will stop him to talk.
"My big goal is to meet as many people as I can," he said.
His route will take him as far west as Fayette County, about 100 miles away, and then north to Indiana County.
In February, Keller announced he would run for the 9th Congressional seat.
He is a Chambersburg native and 1987 graduate of Chambersburg Area Senior High School. He has a bachelor's degree in government, but this is his first bid for office.
Since 1993, he has worked as a computer network consultant for digitalSunrise, the corporate sales and service division of Sunrise Computers in Chambersburg.
Keller has said he thinks the 9th District needs leadership that will take it in a different direction. He emphasized bridging the digital divide and making Internet access more accessible to everyone.
The 9th District includes all or part of 14 counties, including Bedford, Blair, Franklin, Fulton, Huntingdon, Juniata, Clearfield, Mifflin, Perry, Indiana, Somerset, Cambria, Cumberland and Fayette.