skidder

The bridges crossing the SART are as high as the levees on each side of the river, and the trail is on top of those levees I'd guess they are 15-20 feet above the riverbed?. They're truss bridges, pretty well guarded on the sides so you won't fall off . Scroll down on this page and you'll come to a few pictures of the bridge at the south end that goes across from Costa Mesa to Huntington Beach. There's another similar bridge almost next to the 17th street road crossing up in Santa Ana, about 1.5-2 miles south of the 'Orange Crush' freeway interchange. Not sure about the bridges farther inland, maybe other can chime in on those.

Entering and exiting the Santa Ana River Trail in Costa Mesa | Marc Perkins