The Rio Grande is a major river in North America that flows from the Rocky Mountains of Colorado to the Gulf of Mexico. It is approximately 1,900 miles long and is the fourth longest river in the United States. The river forms the border between the United States and Mexico and is an important water source for both countries. The Rio Grande is known for its scenic beauty and is popular for recreational activities such as rafting and fishing. It is also an important habitat for a variety of plant and animal species. The upper reaches of the Rio Grande are located in the high alpine environment of the Rocky Mountains and are known for their beautiful scenery and abundant populations of rainbow and brown trout. These sections of the river are popular among fly fishermen and offer a variety of challenging and rewarding fishing opportunities. The lower sections of the Rio Grande in Colorado are less suited to fly fishing, as they are generally more placid and slower-moving. However, they still offer opportunities for fishing and other recreational activities.

The Rio Grande river in Colorado is known for its abundant populations of rainbow and brown trout. These species are popular among anglers and are highly sought after for their fighting spirit and excellent flavor. The river also supports a variety of other fish species, including brook trout, cutthroat trout, and kokanee salmon. In addition to these game fish, the Rio Grande is also home to a number of non-game fish species, such as sculpin and chub. Overall, the Rio Grande in Colorado offers a diverse and rich fishing environment for anglers of all skill levels.

Currently, low flows make this river very managed.