To sign up for a tour, show up at the eco guide centre (a branch of the official Savannakhet tourism organisation) just east of Talaat Yen plaza on Latsaphanit Road between 08:00 and 4:30 daily.
The smaller the group, the more expensive the tour, so the trick is to sign up for a tour that already has people listed on the sign-in sheet, or you can start one of your own and hope that others follow your lead. It's best to do the latter at least two days in advance of your desired departure date unless you're happy with the group you have. You can also specify a minimum number of people needed to make a group.
Several trekking and cycling tours to the NBCAs are available from the eco guide centre. They vary between one and four days in length and are all inclusive of meals, accommodation and drinks (except alcohol), although it's a good idea to give your local guide a tip if you think they did a good job.
Tours arranged by the eco-guide unit rely on local guides and are a rich resource of information on how the forest has functioned as a natural factory for medicine, food and fuel for the forest-dwelling Lao over the centuries. You'll see wildlife and get a true "back to nature" experience. Although you may not be expecting it on a tour that's billed as a "trek" in a "conservation area" with an "eco-guide", these tours also provide healthy glimpses into traditional Lao culture, with overnight accommodation for multi-day treks in the form of remote village homestays.
Dong Natad is the easiest NBCA to visit as it's only 15 kilometres from the centre of town. You can visit it on your own -- it's about 11 kilometres past Friendship Bridge 2 to the north, across from the salt mines -- but the 'entrance' is via one of several unmarked trails almost completely swallowed up by forest. Even assuming you found your way through the maze of trails to Nong Lom Lake, the overwhelming consensus is you'd be missing out on the best parts of the experience.
The eco-guide unit offers six different tours of Dong Natad. The basic day-trek begins with a visit to a working salt mine, then leads through pristine forest and onto Nong Lom lake. The lake isn't exactly a refreshing spot to take a dip, but its marshy terrain comes to life as the guide explains how it has sustained local people since before memory. After a bit more hiking, the tour takes on a more cultural flavour as you visit a traditional basket and mat weaving village and end the day at the ruins of historic That Ing Hang stupa, which is Savannakhet's principle religious site.
The single-day cycling tour takes you further afield to Bungva Lake, which is more picturesque and larger than Nong Lom. This tour also stops at That Ing Hang stupa and includes 26 kilometres of cycling over a 10-hour time period. The two- and three-day offerings to Dong Natad don't offer too much more in terms of specific sights, but with these you're able to stay in a traditional Lao home, try your hand and voice at Lao music and wake early to give food to monks on their morning alms round. In other words, go for the mulit-day tours if seeking a more complete experience.
Tour prices to Dong Natad vary according to the number of days and size of the group. The basic single-day trek costs US$32 per person for two-three people, $27 for four to seven and $23 for eight or more. The cycling tour is slightly less expensive. Two-day tours cost $62 for two-three people, $50 for four to seven and $45 for eight and up.
Far fewer travellers opt for the three- and four-day treks in Phu Xang Hae and Dong Phu Vieng, but they're great opportunities for anyone looking to get way off the beaten track.
Phu Xang Hae is located 145 kilometres east of Savannakhet town, and the four-day trip includes treks through thick jungle leading to viewpoints overlooking the Annamite mountains, a stop at a cave where the walls have been smoothed by wild elephants scratching themselves, and three nights in a Phutai (a small regional ethnic group) village. The cost for the Phu Xang Hae trip is $235 per person for two-three people, $198 for four to seven and $146 for eight or more.
Dong Phu Vieng is located even further afield, its eastern boundaries stretching almost to the Vietnam border. The three-day tour includes treks through the sacred Dong Sa'kee forest, a peek at dinosaur footprints, a swim in a remote swimming hole, a longtail boat ride on a whitewater river and a couple of nights stay in a Katang (another ethnic minority group) village. The price for the Dong Phu Vieng trip is US $192 per person for two-three people, $146 for four to seven and $117 for eight or more.