A friend and I booked an elephant trek and whitewater rafting combo package while visiting the Chiang Mai in the northern section of Thailand. We used the company called Siam River Adventures and the day was well worth the money. They picked us up from our hotel in Chiang Mai and drove us to the elephant camp that was located on the banks of the Mae Taeng River. We were promptly boarded onto an elephant and take on a riverside trek of about an hour. A large bag of bananas was provided to fill our "vehicle's" insatiable appetite. After this, we were driven upstream where we were provided an excellent Thai meal and given a safety briefing before boarding one of several rafts and launching on the river. The trip was filled with exciting Class IV rapids and our guide was extremely pleasant. If you are in Chiang Mai, there are many options for whitewater rafting and elephant trekking companies, but I would strongly recommend looking at this company. It's well worth the money!