WSP08457

• File Number: 8062
• Description: Federal Water Rights
• State: CO
• Basin: Statewide
• Date: 9/1/1983
• Author: CDOW
• Title: Observations of the Ecology of Colorado Squawfish - Ptychocheilus Lucius - in the Yampa River Colorado - 1982
• Water Supply Pro - Doc Type: Report/Study

INTRODUCTION

The Yampa River originates on the western slope of the Rocky

Mountains near Yampa, Colorado, It is the largest tributary to the

Green River, The Yampa flows first in a northerly and then in a

westerly direction to its confluence with the Green River in Dinosaur

National ~lonument (Fig. 1). The Yampa River can be characterized as a

system of extreme hydrologic events, Dramatic seasonal fluctuations in

flow create equally dramatic changes in temperature, turbidity,

conductivity, and quantity of allochthonous material, These seasonal

varlations in flow and water quality also exhibit long-term pulses

caused by annual variations in precipitation and accumulation of snow in

mountainous regions of the river watershed, Amid these hydrologic

extremes the endemic Colorado squawfish evolved a unique migratory

reproductive strategy.

Historically, migration of Colorado squawfish (Ptvchocheilus

lucius) was considered a predictable summer event in many of the rivers

of western Colorado (Sigler and Miller, 1963; Joseph et al., 1977;
Behnke and Benson, 1980), However, neither origin nor destination of

the migrants was documented, It was assumed that the migration was

related to spawning.

Recent studies, conducted by the U,S. Fish and Wildlife Service

(USFWS), Colorado Division of Wildlife (CDOW), and Utah Division of
Wildlife Resources in the Upper Colorado River basin (Wick et aI" 1981;
Haynes and Muth, 1982; Miller et aI" 1982a,b, 1983b; Tyus et aI"
1982a,b; Radant et aI" 1983) produced new data regarding the movements

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