Serra do Divisor is a national park in Acre, Brazil.
There is no infrastructure for visitors. In order to access the national park, visitors must make their way to Cruzeiro do Sul, a town of about 50,000 Brazilians. If coming by bus, you'll need to leave from the city of Rio Branco. The ride is anywhere from 14 to 17 hours on a passable but very bumpy dirt and tar road. The cost is R$112 (July 2015). If coming from Puerto Maldonado, Peru, you can find a Peruvian colectivo taxi for S/30 into the town of Inapari at the international border (4-hour ride). The town across the border is where Brazilian bus service begins. There is bus service from this town of Assiss Brasil for R$50 real into Rio Branco. The ride is 6 hours into Rio Branco from Assisis Brasil. There are taxi's everywhere and they will pressure you to make the trip in their taxi's for double or triple what the bus service charges from Assisis Brasil. The bus from Assisis Brasil leaves at 6AM getting into Rio Branco at about 1PM. Then you take an overnight at 6:30PM or next day bus leaving at 8AM into Cruzeiro Do Sul. Avoid the overnight bus. It is extremely uncomfortable and makes for very sore muscles and fatigue.
If coming into Rio Branco from somewhere else in Brazil then you'll already be accustomed to the Brasil bus service. If flying directly into Rio Branco, you might as well add an extra leg onto the flight as Cruzeiro do Sul does have a small airport and is only a 1½-hour flight from Rio Branco or 2½-hour flight from the Amazon city of Manaus. Cost is about R$600 from either city and well worth the extra cost.
There is another way into the park on the Peruvian side. You can fly into Iquitos or Pucallpa and either take a 12-hour boat ride or a one hour flight up to the small town of Contamana. From there it is only a one-hour taxi ride up the mountain into the Peruvian side of the park.
Once in Cruzeiro Do Sul, hotel Mosso is a nice hotel with friendly staff. Rooms are R$60 per night (July 2015). Good breakfast and very close to the town square where amazing barbecue, yucca and salad are served at night for R$11.
From Cruzeiro Do Sul, find a ride to Mancio Lima and ask for George at the Hotel Voyage. He runs a motorized boat into the national park for R$800 (July 2015). There are some other park guides and they can charge up to R$1000 for the same trip. There are two small cottages in the national park and they do not provide meals. Bring food and water with you as the locals living in the park do not trade or sell food to outsiders. It takes one whole day by boat into the park where all the waterfalls, mountains, wildlife and true beauty of the untouched Amazon lie. It is generally 12 hours by boat in, one day basking in the waterfalls (hiking in to see them) and leaving the 3rd day returning to Mancio Lima (8 hours). The tour guide may charge more depending on how long you want to stay in the park (3, 4 or 5 days). This trip is for the true adventurist so make sure that you dress for the occasion, bring a flashlight and rubber boots and get plenty of rest the night before you leave for the National Park.