Left on this road is CONCRETE, =1 m.= (1,100 alt., 40 pop.), named by Mrs. Webster Merrifield, whose husband, for many years president of the State university at Grand Forks, was one of the owners of the cement mines once operated here near the source of the Tongue River. At the height of production 500 bbl. were turned out per day, but operations were discontinued when a cheaper type of cement was imported. Left at =43 m.= is a small AGRICULTURAL EXPERIMENTAL STATION, a substation of the State agricultural college at Fargo. LANGDON, =44 m.= (1,612 alt., 1,221 pop.), became Cavalier County seat in 1884, through the efforts, it is said, of a dozen bachelors who, working hard and changing names and apparel often on election day, voted all the sod shacks--whose owners were either absent or not taking time to vote--for miles around. Originally called McHugh for a prominent early settler, the town later adopted the name of Langdon in honor of the man who made the survey for the local branch of the G. N. Ry. and who presented the village with a bell for the school soon to be built. An unusual enterprise in Langdon is the Haymow Theater, a children's organization which has presented plays annually for more than a quarter of a century. Children of some of the first members of the company are now taking part in the plays. Performances are held (_adm. 10c_) during the summer in the loft of the R. T. BURKE BARN (_for directions inquire at post office_). CLYDE, =69 m.= (1,618 alt., 275 pop.), is named for the Clyde River in Scotland. At =86 m.= is a junction with ND 4 (_see Tour 2_), which to =92 m.= unites with ND 5. ROLLA, =108.5 m.= (1,817 alt., 852 pop.), forms the eastern gateway to the lakes and hills of the TURTLE MOUNTAINS, a rolling plateau rising 300 to 400 ft. above the surrounding country. It stretches 40 m. to the W. and about 30 m. N. and S., and is bisected by the international boundary. The mountains were named by the Indians, to whom their outline suggested the form of the sacred turtle. Rolla is the Rolette County seat, and its name is believed to be a contraction of the county name. At Rolla in 1889 was established the short-lived Rolla University, which opened its doors to 45 students, and closed them when lack of funds became pressing. During 15 years of his young manhood John Burke (1859-1937), three times Governor of the State (1907-13), former United States Treasurer (1913-21), and former chief justice of the State supreme court (1935-37), lived in Rolla. Here is the office of the secretary of the International Peace Garden, Inc. (_see below_), where most of the business of the corporation is transacted. At Rolla is the junction with ND 30, a graveled highway.