The most prominent of these Pedro Mountain roads was Coastside Boulevard, the 1914 to 1937 coastal highway 57, which remains in use today as part of the trail network of McNee Ranch State Park.

This routing today is known as Indian Trail, running up from Martini Creek, over Saddle Pass and down the ridge into the present day Willow Brook Estates in the Linda Mar district of Pacifica.

From 1879 to 1914 the routing was changed entirely, called the Half Moon Bay - Colma Road, and transversed over the mountain closer to the ocean on very steep and rutted switchbacks from above the Shamrock Ranch towards Martini Creek.

“Even with a thoroughly reliable driver and trustworthy car,” Motoring magazine warned in 1913, “Pedro Mountain Road is in such poor condition that anyone going this way is simply inviting disaster.” The danger was underscored by a large sign that read: “DANGEROUS FOR AUTOMOBILES—TAKE ROAD VIA SAN MATEO” Motorists who chose to ignore this sign encountered grades as steep as 25 percent in some places.

Hairpin turns called for “the coolest heads, firmest hands, and strongest brakes that a car can have.”[3] This is supported by vintage photographs of the road.

[6] One longtime coastside resident, Charlie Nye, Jr., recalled: "The road coming over Pedro Mountain was terrible, just awful.

"[7] Part of the road begins at a chain link fence at the existing stub in Montara and continues north to Martini Creek.