WSP00003

• File Number: 8200.760
• Description: Yampa River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 4/1/1969
• Author: CWCB - USDA
• Title: Water and Related Land Resources - Yampa River Basin - Colorado and Wyoming
• Water Supply Pro - Doc Type: Report/Study

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period, while Steamboat Springs receives nearly one-half of its II
precipitation as snow in the same period. More than one-third of the
precipitation at Craig occurs during the growing season. Steamboat
Springs receives little more than one-fifth for the same period. Summer II
precipitation generally takes the form of showers which contribute little
to overall water supplies. Winter snow accumulation is the principal
source of streamflow. In the high areas precipitation is typically moun- '.
tain thundershowers with only localized areas occasionally receiving
severe intensities. At lower elevations, summer showers are affected by
convective conditions and frequently occur as "cloudbursts". Floods are I
of short duration and low total water production, but peak flows are high.

Evaporation losses from existing small ponds and reservoirs range from 17
to 20 inches per year depending on their location in the basin. It,

PhysioRraphy and GeoloRY I

Physiography

Most of the Yampa River Basin lies within the southern part of the
Wyoming Basin physiographic province, a plateau area underlain by wide-
spread deposits of relatively soft sedimentary rocks, bordered in part by
abrupt mountain slopes, and containing isolated mountain ridges. Narrow
areas along the eastern and southeastern margins of the basin are occu-
pied by the Park Range and White River Plateau portions of the Southern
Rocky Mountains physiographic province. The Uinta Mountains portion of
the Middle Rocky Mountains physiographic province comprises an area at
the southwestern edge of the basin. Elevations vary from 5,000 feet
where the Green River crosses the Colorado-Utah state line to 12,493 feet
on Flattop Mountain in the southeastern part of the basin.

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The Park Range and White River Plateau areas form the headwaters for most
of the major streams. The Park Range, extending along the eastern edge
of the basin, consists mainly of broad mountain slopes about 10,000 feet
in elevation. The high mountain valleys which drain these slopes are
generally broad and open. For a distance of about 20 miles south of the
Wyoming border the center of the Park Range is a strongly glaciated ridge
with peaks rising to above 12,000 feet elevation.

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The White River Plateau, lying along the southeast margins of the basin,
consists mainly of basalt uplands between 10,000 and 11,500 feet in ele-
vation, with a few peaks above 12,000 feet. The upland surface of the
plateau is dotted with numerous shallow, flatbottomed depressions, many
of which contain lakes. The borders of the plateau are approximately
1,000 to 2,000 feet above the surrounding terrain and have vertical
cliffs, angular mesas, and steep-sided canyons.

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