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OD!1l8 -2- this seotion is indioated on Plute II. On tre ea.st side a spur of the San JUIl.l1S runs north forming the divide betwaen the Unoompahgre Il.I1d Ci~ marron Rivers. This short range is oomposed of a. series of high peaks. The balanoe of the Ouray-Colona. seotion is made up of foothills well udapted to oattle raising. The DlIl.in tributaries entering tre River in this section are De.llas Creek draining the wstern portion Il.I1d Cow Creek. l'lhioh drains the greater part of the eastern side. The bulk of the ir- rigated land in this seoti on lies along these t\'lO tributaries and the main stem of the river. The two upper sections of the basin oomprise 437 square miles or about 25% ~f the total a.rea and produoe approximately 85% of the stream flow. A short distanoe above Colons. the valley begins to widen more rapidly and spreads in the shape of a triang;le from that point to a base 14 miles in length along the Gunnison River in the vioinity of Delta. The Unoompahgre flows northwest through this triangle and empties into the Gunnison River about a half-mile northwast of Delta. This valley section is ohuraoterized by a series of broad arable mesns, upon whioh 75% of the agrioultural area of the basin is located. It is this third section with whioh we are ohiefly oonoerned in this report. The Unoom- pahgre Project area of the U. S. Burenu of Reolamation is located there. Investigations oarried on during 1938-1941, details of whioh follow in Part II, were made in the Colona-Delta section, whioh will be generally referred to as the lower Unoompahgre Valley. Details pertaining to the lowar valley a.re omitted from Plate II and shom an Plates IV, V, and VI. 3. Elevations and TopographYI Within the basin of the Unoompo.hgre, to the scuthwest. south and eust of Ouray in a radius of about 8 miles lies one of the most rug- ged seotions of the State. In this aren there are two pea.ks huving elevations over 14.000 feet, not less than 15 peaks between 13.000 and 14,000 feet and numerous others between 12,000 and 13,000 feet. Ouray rests at the foot of these peaks a.t nn elevation of 7,700 feet. (7).* Peaks of the north spur of the San Juans, (mentioned in seo- tion 2), range from ll,3tJ8 feet to 14,020 feet~ This group of mountains y,tls first mentioned by Hayden (13) in his desoription of the Unoompa.hgre Va.lley, where he says I "The peaks . . . . show beautifully the influenoe of the ohurnoter of rooks upon erosion. The valleys ware proba.bly onoe the seat of glaoiers. although the . Numbers in parenthesis ( ) refer to publioations oited in the bibliography.