this is believed to be only temporary, induced by the drought of last year. No control measures are deemed necessary. Another serious problem has arisen in the Yosemite, in the form of a disease or blight accompanied by insect activity in the white and red fir forests. This apparently is a disease which attacks the trees just beneath the bark, and would not kill the trees were it not generally followed by bark beetle attacks. Samples of bark have been collected, and will be studied by Bureau of Entomology experts during the winter. If the policy of making annual appropriations for insect control work in the parks and monuments is continued, it will be possible for the Bureau of Entomology to detail one or two of its experts to devote their entire time to such work. This is very desirable, in order that the highest degree of efficiency may be attained. START MADE ON ROADSIDE CLEAN-UP WORK In my preceding annual report I brought out the fact that dead and down timber and stumps along the roadsides of the parks not only were a blot on the landscape from a scenic standpoint but also provided a serious fire hazard, and I emphasized the importance of cleaning up such roadside conditions. A visitor to Yellowstone National Park last summer was much impressed, through personal observation, with the need for such roadside clean-up, and provided funds with which, as an experiment, two half-mile stretches of road, one heavily littered with dead and down timber and one requiring only a light clean-up, were cleared. Such satisfactory and economical result were obtained that this park friend then authorized the expenditure of sufficient funds to clear up as much of the road south from park headquarters at Mammoth Hot Springs as could be accomplished while favorable weather conditions prevailed. This work was carried on to the close of November, when stormy weather made continuation impossible, and nearly 11 miles of road were improved at a cost of approximately $4,500. The roadsides were cleared from 15 to 100 feet back from the ditch line of the road on both sides, depending upon visibility of the roadsides from an automobile driven along the road. Winter snows restored natural conditions, so that by the time the travel season opened all scars left by the clean-up work had disappeared. Some additional work was done this spring at a cost of about $1,000. This same park friend has recently authorized the expenditure of an additional $5,000 on further clean-up work, which was commenced early in September, and will be pushed while favorable weather conditions prevail. THE SANITATION PROBLEM IN THE PARKS Where thousands of motorists visit the parks and must be accommodated in the public camp grounds, it is inevitable that serious problems of sanitation are encountered and must be solved. In some of the Yellowstone camp grounds as many as 2,000 people are sheltered a night, and in the Yosemite, where in a small space of about 4 square miles, all the hotels and accommodations of the public operators, as well as the free public camps, are located, the sani tation problems are equal to those of the small city. In the latter park at the height of the season from ten to twelve thousand people a day are housed on the floor of the valley, and the number of campers there, as well as in all the other parks, steadily increases. Through the excellent cooperation of the United States Public Health Service in detailing their expert sanitary engineers to study these problems, the public is assured of every precaution in safeguarding its health. The advice of that service is carefully followed, and as a result the National Park Service feels that it can say that sanitation in the parks is on as high a standard as it can be carried forward under available appropriations. The great need, however, is not alone for enlargement of existing public camp grounds in the major parks, but the establishment of others well developed and equipped from a sanitation standpoint. This includes proper garbage and sewage disposal systems, fresh water and the control of mosquitoes, flies, and odors. It is imperative that from year to year more funds must be secured to carry this work forward, and this is considered one of the most important of the duties devolving upon the service in providing for its guests. ARCHEOLOGICAL WORK General restoration and repair work on the historic and prehistoric ruins in the Aztec, Casa Grande, Chaco Canyon, Gran Quivira, and Pipe Spring National Monuments was carried on during the year with the funds available. This work was done under the general supervision of the superintendent of southwestern monuments. While repairing the walls of the Casa Grande Ruin, a rare cache of turquoise mosaics was uncovered. Three pieces of mosaic were, found, two of them in the form of birds and the third representing a turtle. The largest bird is the best preserved. This was made on a wooden core, with the mosaics placed in wax. Each bit of stone was worked out to a pyramidal shape and 492 stones used in the bird alone, which measures about 41/2 inches from wing tip to wing tip. In making the turtle, the largest of the designs, 1,129 stones were used. With these mosaics were found a set of perfectly matched turquoise pendants and over 900 shell beads. The discovery of the mosaics is of remarkable scientific interest, for they show that the artisanship of the prehistoric peoples once inhabiting the Casa Grande was equal to any other southwestern culture, in fact closely approached that of modern times in beauty of design and workmanship. The policy of repairing ruins already excavated, in preference to carrying on exploration work, was followed again in the Mesa Verde National Park during the year just ended. The park superintendent is a trained archeologist, and under his supervision the ruins were put in the best condition that has obtained for years. During the winter Spruce Tree House north refuse space was excavated with funds donated by an interested park friend. In the course of this work considerable interesting material was collected for the new museum. The National Geographic Society continued its fifth year of exploration work at the Chaco Canyon National Monument under the direction of Neil M. Judd of the United States National Museum. Work was continued on the Pueblo Bonito and Pueblo del Arroyo ruins under the permits granted the Geographic Society in 1921 and 1924 and in addition permission was given by the department last year for the society's representative to conduct archeological explorations at three small-house ruins on the public domain in the Chaco Canyon drainage in order to clarify certain archeological problems which developed in connection with the Pueblo Bonito and Pueblo del Arroyo explorations. This year's work completes the five-year exploration project of the National Geographic Society. During the course of the work evidence was secured that in the height of its usefulness Pueblo Bonito had 800 rooms and 32 kivas, and housed approximately 1,200 inhabitants. A valuable find here was a turquoise necklace in four strands, containing over 2,500 matched beads, estimated to be over 1,000 years old. Much other valuable material was brought to light, and will be exhibited in the museum of the National Geographic Society and the United States National Museum in Washington. EDUCATIONAL WORK IN THE PARKS Nature study has a universal appeal, even when carried on only through the medium of books. The opportunities afforded in the national parks for such study among nature's own chosen conditions brought about a constantly increasing demand for intelligent interpretation of the various natural features in relation to their surroundings. Visitors to the parks want to understand more not only about the rock formations and the geologic history of the particular area in question, but about the trees, flowers, birds, and mammals, and the Indians who are inseparably connected with the historic atmosphere of the region. In fact, everything that is preserved in its natural state in the national parks is an object of intense interest to visitors, and a ready subject for study and explanation. Recognizing this consistent demand, I have endeavored for the past six years gradually to develop opportunities in the parks for students and visitors, by direct contact with the handiwork of nature, to take an intensive course in natural history, and during the past year the results have been particularly gratifying. Biologists, geologists, and other scientists, with their classes, have enthusiastically made use of the opportunities for research and investigation afforded in the national parks. Now, however, our efforts are directed toward making it practicable for the average visitor to the park without much time at his disposal for personal research work or without the necessary scientific background to work things out for himself to acquire a practical knowledge of the natural history and the other exhibits of natural phenomena. Your approval of the educational plan I presented to you last April made possible the beginning of expansion of the educational work along well-defined lines. The chief park naturalist, who during the period of the construction of the Yosemite Museum acted as the agent of the American Association of Museums and during that time received no salary from the Government, was taken over on the service salary roll upon the completion of the museum building. He has been engaged during the summer in building up an educational division that coordinates the natural history work of the |