RANGE PRESERVATION AND EROSION CONTROL. 
33 
is smoothed out by means of a homemade terrace drag (fig. 8). The 
drag is constructed in a V-shape and can be made any width provided 
the proportions are followed as given in the sketch. In order that 
the drag may work effectively one or two men usually stand on the 
crosspiece supporting the side beams. As soon as the terrace is well 
smoothed it is ready for planting. 
Planting early in the spring before growth has started has given 
the best results; and since the soil can not be worked satisfactorily 
at that time terraces can best be established in the autumn. At the 
intersection of the more prominent gullies and the terraces, the 
former are built up with rock butts and overlaid with soil. In order 
to hold the terrace soil as effectively as possible, the terraces are 
planted to such soil-binding species as wild gooseberry (GrossvZaria) , 
mountain elder (Sambucus) , yellow brush (Chrysothamnus) , sweet 
sage (Artemisia), yarrow (Achillea) , and several species of sub- 
Fig. 8. — Terrace drag. 
alpine grasses. Since seed of native grasses, which soon become 
firmly established on the terraces, can not be purchased from com- 
mercial seed houses it has been necessary to collect seed wherever a 
good crop developed naturally. However, following the establish- 
ment of the terrace a great deal of seed of native species is caught 
during the natural seed dissemination period in the autumn, and in 
two seasons or so the terraces become fairly well vegetated. As 
the soil is enriched through the accumulation of decayed vegetable 
matter, conditions for growth are gradually made more favorable 
and the vegetation develops luxuriantly. 
The area experimented with, prior to the establishment of the ter- 
races and fill work, had been subject each season to serious erosion. 
Since the establishment of the terraces and supplemental work, no 
erosion whatsoever has occurred and the lands are generally becoming 
