Here is a 1 minute time lapse video I put together for a bridge that a crew of mine constructed in 2008 on the Salmon-Challis National Forest. The bridge was completed in just over a week using native materials. It is located on Kane Lake Trail.

My trail crew recently replaced a bridge on Kane Lake Trail in the Salmon-Challis National Forest. The old bridge had collapsed into the stream and a hiker had recently broken a leg trying to cross over it.
We started by removing the old bridge and then building two large timber abutments to reduce the length of the bridge from about 30 feet to 22 feet. This involved a large retaining wall made of timber and filled in with large rocks and crush.
After completing the abutments and placing the sills, we started on the stringers. We made some amazing saddle notches in the stringers that were nearly 20 inches in diameter on the fat end.