farming, particularly potatoes and grain. Solid basalt can be found beneath the soil throughout most of the valley and exposed outcrops are common. Other types of rock that are common in the area are limestone and shale. These non-volcanic rock beds are rich with fossils of prehistoric marine life once native to the inland sea that covered the area some 280 million years ago, ranging from well preserved molluscan shells, to small fish. Trilobite fossils can often be found in local shale deposits. The inland sea was also responsible for the vast phosphate deposits that lie north of Grace and are a vital part of the area's economy. The Bear River runs through Black Canyon which originates northwest of town and extends approximately south. Approximately one-half mile downstream from the point of origin, the Black Canyon forms a sharp gorge with steep walls of black basalt cliffs. At this point the gorge is only about wide and nearly deep. The Wasatch Fault is visible from Grace due to the sharp displacement that creates a small bench at the foot of the mountains. Mild to moderate earthquakes have been reported to originate at the fault. Demographics 2010 census As of the census of 2010, there were 915 people, 366 households, and 266 families residing in the city. The population density was . There were 400 housing units at an average density of . The racial makeup of the city was 96.9% White, 0.1% African American, 0.4% Native American, 0.1% Asian, 0.1% Pacific Islander, 1.5% from other races, and 0.8% from two or more races. Hispanic or Latino of any race were 4.2% of the population. There were 366 households, of which 33.6% had children under the age of 18 living with them, 62.0% were married couples living together, 5.7% had a female householder with no husband present, 4.9% had a male householder with no wife present, and 27.3% were non-families. 24.6% of all households were made up of individuals, and 13.7% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 3.00. The median age in the city was 38.9 years. 26.3% of residents were under the age of 18; 6.1% were between the ages of 18 and 24; 23.3% were from 25 to 44; 25.9% were from 45 to 64; and 18.5% were 65 years of