The incident occurred Sunday in Rancho Corral de Tierra, the San Francisco Chronicle reported Wednesday. The area in the hills south of San Francisco was recently added to the Golden Gate National Recreation Area.
A spokesman says the ranger stunned Gary Hesterberg of Montara after Hesterberg first gave him a phony name and then started to walk away. Hesterberg told the ranger he should not use the weapon because of his heart condition, the spokesman said.
Paramedics determined Hesterberg had suffered no ill effects.
"Many of my constituents are understandably angered by what appears to be an excessive use of force by a park ranger," Rep. Jackie Speier, D-Calif., said in a letter to the national recreation area's director. "From the information I have to date, it does not appear that the use of a Taser was warranted."