Is the Paria River a pariah?

Authors: David Rogowski, John Fennell

Year: 2025

Abstract

Small desert streams that are tributaries to larger rivers can be important habitats. In highly altered river basins, like the Colorado River, unregulated tributaries can provide important spawning and rearing habitat for native fishes. While there are quite a few tributaries to the Colorado River within the Grand Canyon, such as the Little Colorado River, Havasu Creek, Bright Angel Creek, etc. … there is only one tributary within Glen Canyon, the Paria River. The Paria river is approximately 153 km in length, with an average flow of 0.79 m3/s (minimum 0.028 and maximum of 460 m3/s) and is known for its muddy and turbid water. The Paria River is an important source of sediment within the Colorado River downstream of Glen Canyon Dam, and it is not known for its fishes. While the Colorado River and many of its tributaries have monitoring programs in place, none occur on the Paria River. In the spring of 2025 we placed two remote PIT tag antennas in the Paria River for two months and detected 679 unique fishes during that time: 587 Flannelmouth Sucker, 8 Bluehead Sucker, 1 Rainbow Trout and 83 unassigned fish. The importance of the Paria River to populations of native fishes within Glen Canyon and Grand Canyon is unknown at this time.