Tracing the Amazon from its headwaters...

Here's a bridge: https://www.google.com/maps/@-15.2762023,-71.6326301,334m/da...

Here's a bridge: https://www.google.com/maps/@-15.1768982,-71.6372406,233m/da...

Here's a couple of bridges: https://www.google.com/maps/@-14.8748328,-71.5192037,233m/da...

Here's a bridge: https://www.google.com/maps/@-14.8073581,-71.4882189,863m/da...

Here's a bridge: https://www.google.com/maps/@-14.7501513,-71.4792706,326m/da...

Here's a bridge (with some spectacular ancient ruins just north of it, wow!): https://www.google.com/maps/@-14.7317275,-71.4653133,372m/da...

Here's a bridge: https://www.google.com/maps/@-14.6865893,-71.4459353,271m/da...

Here's a bridge: https://www.google.com/maps/@-14.6503598,-71.4346162,335m/da...

Here's a bridge: https://www.google.com/maps/@-14.6068402,-71.4539496,370m/da...

Here's a bridge: https://www.google.com/maps/@-14.5375724,-71.4662274,376m/da...

Here's a bridge: https://www.google.com/maps/@-14.4966649,-71.4655178,619m/da...

Here's a bridge: https://www.google.com/maps/@-14.4821393,-71.4651525,932m/da...

Here's a bridge, fascinating remnants of high-intensity agriculture in the area. Clearly supported a much larger population during pre-Columbian times: https://www.google.com/maps/@-14.4041017,-71.4689323,467m/da...

Here's a couple of bridges, including a famous rope bridge: https://www.google.com/maps/@-14.3821426,-71.4849719,637m/da...

Here's a bridge: https://www.google.com/maps/@-14.2970991,-71.5081793,491m/da...

Here's a bridge: https://www.google.com/maps/@-14.2257273,-71.5213399,828m/da...

Here's a bridge: https://www.google.com/maps/@-14.1689771,-71.5576715,754m/da...

Here's a bridge: https://www.google.com/maps/@-14.1260513,-71.6607489,453m/da...

Here's a bridge: https://www.google.com/maps/@-13.9539948,-71.7544463,863m/da...

Here's a bridge: https://www.google.com/maps/@-13.932637,-71.7777958,853m/dat...

Here's a bridge, with Streetview! The former bridge looks pretty dodgy: https://www.google.com/maps/@-13.8145316,-71.8335396,3a,60y,...

Here's a bridge: https://www.google.com/maps/@-13.8304518,-71.942204,375m/dat...

Here's a bridge: https://www.google.com/maps/@-13.8211571,-71.9706923,320m/da...

Here's a bridge, with an ex-bridge just upstream: https://www.google.com/maps/@-13.7749211,-72.0847456,168m/da...

I don't understand why there's a bridge here, but there is: https://www.google.com/maps/@-13.77597,-72.0966336,194m/data...

Here's a pre-bridge: https://www.google.com/maps/@-13.6966954,-72.2455627,451m/da...

Here's a bridge: https://www.google.com/maps/@-13.6901983,-72.3356296,515m/da...

Here's a bridge, with more streetview: https://www.google.com/maps/@-13.5627059,-72.5751752,3a,60y,...

Here's a bridge: https://www.google.com/maps/@-13.4215974,-72.852207,437m/dat...

Here's a bridge: https://www.google.com/maps/@-13.4163366,-72.8835264,419m/da...

Here's a bridge: https://www.google.com/maps/@-13.4450156,-73.1816146,699m/da...

Here's a bridge: https://www.google.com/maps/@-13.3103693,-73.329247,409m/dat...

Now we're starting to get into lowlands jungle, but still, here's a bridge: https://www.google.com/maps/@-12.6227864,-73.7872767,846m/da...

...And I believe that is indeed the last one.