512 



ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



ranges at an olovation of moro than 10,000 feet. The Sevier-Cove 

 Fort in soutli Utah and the Fourth of July Can3''on in Idaho are im- 

 portant trunk-Hne roads wliich will be opened to traffic at the close 

 of the present construction season. The Arroyo-Seco and the San 

 Gabriel projects are of sj)ecial interest to the people of southern Cali- 

 fornia. Extremely heavy work is encountered on the San Gabriel, 

 where the excavation for the 16-foot graded width averages 45,000 

 cubic yards to the mile. 



To meet the wide range of conditions and varying traffic require- 

 ments it is necessary to allow considerable latitude m the standards 

 of construction. Thus, for a forest protection road such as the Greer- 

 Bungalow in Idaho the form of construction is simpl}^ graded earth 

 8 feet in width. This road will be primarily for the protection and 

 administration of the forest area, although some development is 

 expected to result from the improvement. In contrast with this is 

 the Alberton project in Montana, which is part of a trunk highway 

 and which is from 18 to 22 feet in width. 



In the accompanying tabulations the activities of this bureau on 

 forest road work have been summarized. All work which has been 

 done under the 10 per cent fund, section 8 of the Federal-aid act, 

 the Post Office appropriation, and with cooperative funds has been 

 included in these tabulations. 



Preliminary engineering investigations have been made on 4,588 

 miles of road. Siu-veys and plans have been completed or are in the 

 process of preparation for about 2,200 miles of highways. 



Construction is completed or in progress on 1,600 miles at an esti- 

 mated cost of $12,000,000. This is an average cost of $7,500 per 

 mile, which includes all engineering expenditures. In addition a 

 number of cooperative projects have been built by the States, On 

 these projects the surveys, plans and construction work are done by 

 the States subject to the approval of the department. 



Engineering investigations and reconnoissayice surveys. 



