Opponents then filed into Matheson's office to deliver written comments to the congressman. The line stretched out of the office and into the hallway.
Bryant Riddle of Wallsburg described himself as a Republican who has voted for Matheson. "But I won't again if he votes for this" health care legislation, he said.
Riddle decried the legislation as adding to government. He said Congress should focus on removing waste in health care spending and increasing competition for services.
"Nobody has any confidence in government," he said.
Carolyn Sharette, a nurse who said she has traveled abroad on humanitarian missions, agreed the cost of reform is too high.
"We're already doing a good job and we can fix things," she said.
Opponents planned another rally at Matheson's office at noon Saturday.
On the other side of the issue, 995 Utah health care providers, including 552 physicians, signed a letter delivered to Matheson on Friday urging him to vote yes. The letter came after the group calling itself the Utah White Coats this week published newspaper ads and held a press event signaling their support for the health care reform bill.
"Now is the time for Congress and Congressman Matheson to vote yes for the health of our children and the financial health of the nation they are to inherit," pediatrician Ellie Brownstein said in a statement. "We cannot wait another year, another day, another hour to get started on meaningful reforms. This is our chance; let's get it done."
In addition, the Utah Health Policy Project planned to operate a phone tree from 11 a.m. to 3 p.m. Saturday to urge supporters to contact Matheson. The nonprofit health care reform advocacy group's Judi Hilman said Democratic state lawmakers have contacted Matheson and a group of religious leaders organized as the Coalition of Religious Groups also Friday delivered a letter urging his support for the legislation.
Hilman thinks supporters have a shot at convincing Matheson to vote "yes."
"We recognize the risk but it's a risk worth taking," she said.
Tribune reporter Lisa Carricaburu contributed to this story.