If my reader were to visit the Pikes Peak region during spring or fall he would doubtless encounter large gangs of men planting young trees on the barren mountain slopes. Under the proper supervision of Forest officers some of the men will be seen digging holes with a mattock while others are coming directly behind them with bags or boxes with wet moss or burlap, containing small trees. These men are called respectively the diggers and planters. Two men will plant from 500 to 1,000 trees a day, depending upon how deep the holes must be dug to accommodate the roots, whether the ground is bare or covered with sod, whether the land is mountainous or level, and many other factors. In this way Uncle Sam plants his denuded areas in the Forests, so that they will be producing _timber_ for future generations instead of useless _brush_ or _tree weeds_. The great variety of climatic and topographic conditions included in the National Forest area makes the problem of tree planting infinitely complex. Nursery stock must be raised in each region having similar climatic conditions, and in each of these regions different methods of planting must be used, depending upon local conditions. The semi-arid mesas of Arizona and New Mexico present different planting problems from the humid forest regions of Oregon and Washington; the methods used in the sandhills of Nebraska and the sand plains of Michigan cannot be applied in full on the high mountain slopes of Colorado; nor are the planting problems in the vast chaparral areas of northern California anything like those encountered in the mountains of Idaho, or in the prairie States of the Middle West, or in the Black Hills. Then, again, the reforestation problems of the chaparral fields of southern California are more perplexing than any I have mentioned above. [Illustration: Figure 28. A planting crew at work setting out small trees. The man ahead digs the hole, and the man behind plants the tree. Wasatch National Forest, Utah] THE ORGANIZATION AND SCOPE OF FOREST EXPERIMENTS AND INVESTIGATIONS