They are off the beaten track but could be combined with overland entry into Brazil or a tour itself for history buffs. The road as far as San Javier is good, about 4 hours from Santa cruz. The extension to Concepcion is in the process of being paved. Traffic is routed on rough temporary lanes beside the main road. Your vehicle should be 4X4.
Busses are able to make the clearance.
Once paved this area will become more popular. You will see many people picking cotton by hand which will be shipped to the mills in La Paz and Peru. The highway is presently crammed with trucks filled with soy. The drivers in this area are acutally quite polite. THe most beautiful farms belong to a Mennonite colony.