All the rivers I saw in Thailand were the color of yellow ochre, carrying silt. The Mae Ping runs southward through Chiang Mai, eventually joining the Chao Phraya running through Bangkok. Its waters make the trip all the way from the northernmost hills down to the Gulf of Thailand.
This is the view from our hotel dining room. The boat is headed north. We took a river cruise on one of these long-tailed boats. The long tail is the motor with its very long stem down to the propeller. Probably in the past the long stem was a sweep oar. Particular to shallow waters.