Problems have delayed exploitation of tar sands in Alberta, but they have certainly not halted it. One by one, these problems have been overcome until, today, tar sands are the most promising near term alternative source of fossil fuels. One company has been mining tar sands and extracting oil from them for 10 yr, the last 2 yr at a profit. A second, much larger plant is now about 95% complete, and a third plant and possible fourth are on the drawing board. More than 20 companies have operated pilot projects for in situ recovery of oil from the tar sands. About 16 of these pilot projects are still in operation and one commercial facility may be under construction within 2 yr. The greatest immediate beneficiary of this activity will be Canada, where most of the work is taking place. The development is described in some detail.