St. Patrick's Day parade weekend brings large crowds to Pittsburgh.

Pittsburgh will host its annual St. Patrick's Day parade Saturday, following the Parade Day Dash at 8 a.m. and with the parade starting at 10 a.m.; transit detours and a police briefing are planned.

Pittsburgh will host its annual St. Patrick's Day parade Saturday as the city prepares for a large downtown celebration of Irish heritage. The event is one of the oldest and largest in the country, tracing back to 1869. Before the parade, the Parade Day Dash will begin at 8 a.m., and the parade is scheduled to start at 10 a.m. City officials have announced transit detours and a police briefing ahead of the weekend. Key details: - The Parade Day Dash begins at 8 a.m. Saturday and includes a 5K race and a 1-mile family fun run/walk through parts of the North Shore and Downtown. - The St. Patrick's Day parade will start at 10 a.m. near the Greyhound bus station on Liberty Avenue, travel along Grant Street and the Boulevard of the Allies, and end beyond Stanwix Street near Commonwealth Place. - The parade dates back to 1869 and traditionally features step dancers, marching bands, military members, and community organizations. - Pittsburgh Regional Transit said more than 50 bus routes will be detoured; most detours are expected to begin around 7 a.m. Saturday and end around 2 p.m., with some remaining in place until 5 p.m. - Molly McKenna was named this year's Miss Smiling Irish Eyes, with Kennedy Kuntz and Sidney Hoover as court maidens; the crowning is set for a Friday luncheon at The Rivers Club. - Pittsburgh Bureau of Police Chief Jason Lando is expected to provide a briefing Friday afternoon about safety measures for the weekend. Summary: The parade could bring hundreds of thousands of people Downtown and will affect transit and local movement across the city. Officials will hold a police briefing Friday and the weekend's scheduled events — the Parade Day Dash and the parade — will take place Saturday as announced.