Top 10 fastest-growing states - CBS News Photo taken August 21, 2013 shows an oil well near Tioga, North Dakota.&nbsp; The fastest-growing state in the U.S. isn't one that grabs many headlines. It's not California or Texas or Florida. It's North Dakota. The huge landmass in the Upper Midwest, with a population smaller than Rhode Island, has seen the highest population growth over the past year, and the highest rate of growth since the 2010 Census, according to the Bureau's recently-released figures. Although the U.S. Census Bureau hasn't released more specific information detailing whether the population growth among the states is coming from immigration or new births, the growth in North Dakota is obvious. Its growth has to do with shale deposits, said Lisa Neidert, a data scientist at the Population Studies Center Institute for Social Research at the University of Michigan. The shale deposits in the West mean booming oil and gas jobs and that is fueling growth not just in North Dakota, but South Dakota and Wyoming, which all cracked the top 20 states in population growth for the first time. Other states in the top 10 grew for other reasons, Neidert said. For Utah, which trails North Dakota, the growth may be more organic -- there are simply more babies born there than folks who die. Then there are states such as Texas, which has a growing native population and an immigrant population relocating from other states.