Three Republicans and four Democrat senators introduced legislation Wednesday to extend a program aimed at recovering endangered fish in the upper Colorado River Basin.

The legislation would extend the program until 2023. It includes three states, including Colorado, in the program that was designed to recover the Colorado pikeminnow, razorback sucker and the humpback and bonytail chubs.

The program was established in 1988 as a way of recovering the fish while also allowing development of the river on the Western Slope, in Utah and downstream.

It's "a great example of a partnership between federal, state, and local agencies to promote conservation," Sen. Cory Gardner, R-Colo., said in a statement.

The bill "provides the resources to continue recovery efforts in the Upper Colorado River and to ensure that these endangered fish species are protected for years to come," Sen. Michael Bennet, D-Colo., said.

Program officials had voiced optimism that they might be able to remove the pikeminnow from the endangered species list, but told The Daily Sentinel that the pikeminnow is falling prey to walleye in the Colorado River below the Grand Valley.

Predation by walleye is a setback to the hopes of removing the pikeminnow from the endangered species list or "downlisting" it as threatened.

The bill also was introduced by Sens. Orrin Hatch, R-Utah, and Martin Heinrich and Tom Udall, both New Mexico Democrats.

A Utah Republican elected this month, John Curtis, introduced companion legislation in the House.