Minnesota Department of Highways

This photograph depicts the historic entrance to the Cascade Falls trail circa 1935.

This photo depicts Arthur R. Nichols, the Minnesota landscape architect who designed Cascade River Wayside, sitting on the wall of the overlook, with Lake Superior and TH 61 in the background. This photo was taken circa 1935.

This photograph depicts the Cascade River Wayside Historic Roadside property from the hillside, looking over Lake Superior. This photo was taken circa 1936.

This is a photo of Craigie Flour Mill wheel and metal sign, taken sometime in the 1930s. The metal sign reads the following: Craigie Flour Mill Near this spot James Craigie of Aberdeen, Scotland, who came to Otter Tail County about 1868 built the first grist mill in the county in 1870. The mill stones and wheel were imported from Scotland. Craigie and his wife were drowned in Otter Tail Lake in 1872 and after long litigation the mill was torn down.

This is a photo of Craigie Flour Mill Historical Marker viewed between large multi-trunk trees in 1940.

This is a photo of Craigie Flour Mill Historical Marker viewed from the front in 1940.

On highway construction projects it is necessary to determine moisture contents of soils and aggregates in connection with earthwork, subbase, base, concrete, and bituminous construction. This determination by the present conventional methods is time consuming, and there has been increasing criticism by contractors that tests of this type are causing delays in the progress of their work. Consequently more rapid methods have been sought for making reliable moisture control tests particularly on base materials and embankment soils. The purpose of this investigation was to determine the accuracy and time saving possibilities of the Calcium Carbide Gas Pressure (CCGP) Moisture Tester when used as a field testing device in comparison with conventional field methods for moisture content determination. This report presents the results of extensive field tests with the instrument. A previous study (Investigation No. 122) had established that moisture contents can be accurately determined with this device under the ideal working conditions of the laboratory. Moisture testers were placed on 14 field projects selected so that the widest possible range of soil types could be tested. Some base and subbase materials were also tested.

This investigation is conducted every year for the purpose of securing information as to the compressive strength and thickness of concrete pavements as constructed under present methods, and to ascertain these factors as they pertain to specification requirements. The following data are obtained for each core drilled: project number, station and location with respect to center line at which each core was drilled, date concrete was placed, date drilled, date core was tested, the height, strengths, and diameter of each core. In the summary of results some of the data is omitted and some is indicated in a different form. The date placed is omitted and the age when drilled and the age when tested is used in place of the drilling and testing dates. The height of the core as shown in the report is the height prior to capping. The location from which the core was taken is measured in the field and the data submitted with the cores for use in the report. Side cores were generally taken two feet from the outer edge of the pavement, and the center cores were taken two to six feet from the center line.

Concrete pavements, particularly In the northern states, are subjected to stresses from climatic changes which not. only affect the load carrying capacity of the slab, but also the life expectancy or the durability of the structure. It was for the purpose of securing additional data to use in computing total stresses under load, and to determine durability that this investigation was started. Measurements have been taken over a twelve-month period. The method of taking measurements, and a summary of the data obtained are shown graphically.

The establishment of good vegetative cover and the control of erosion are two continuing problems being amplified by the expanding and changing highway program. Present methods of seeding, mulching and control of erosion have not kept pace with the advancing roadbuilding technology. Consequently, Maintenance Engineers are inheriting miles of new roadway annually many of which contain serious erosion problems. Six glaring examples of poor vegetative establishment and detrimental erosion became extremely serious in Minnesota during the summer of 1961. A pilot study was set up on these six problem areas to comparatively evaluate various methods of controlling the flow of water, slope preparation and topsoiling, seeding and fertilizing, and to evaluate a number of commercial mulches and erosion control products such as fiberglass, jute and paper fiber nettings, and plastic resin spray material. The major conclusion of the report is that present methods of establishment of vegetation and erosion control can be improved. Recommended improvements to present methods are: (1) sodded or lined ditches, dikes, and flumes should be used more freely where water flow is concentrated; (2) the seedbed should be prepared with agricultural equipment and operated on the contour to provide shallow ridges or furrows; (3) seed should be selected for maximum compatibility with the fertility level of the available topsoil and should be sown with equipment that will not damage or nullify the preparatory work; (4) asphalt emulsion should be used as a binder for hay and straw mulches; (5) jute netting should be used primarily in high discharge ditches; (6) bituminous treated fiberglass blankets may be used in high velocity, high discharge ditches; and (7) mowings should be made to a 4 inch height or greater to make the turf more resistant to drought and weed infestation. Further research is recommended on many of the items included in the pilot study.