A pedestrian was struck by a car and critically injured Monday night in upper Montgomery County, police said.

Yessenia M. Martinez Rivas, 37, of Lamont Lane in Gaithersburg was struck about 5:30 p.m. in the Gaithersburg area on Muddy Branch Road near Suffield Drive, said Officer Britta Thomas, a police spokeswoman. The site is within a half mile of the woman’s home.

She was in critical condition at a hospital Monday night, Thomas said. The incident remained under investigation, she said.