The California-Nevada state border.
Nevada became a State in 1864 a full 19 years behind Texas.
California and Nevada could be joined and become a state. Yes it is possible. Will it happen? No. Both now have two senators. If they joined they would lose two senators. They would lose power. That will not happen. California is now broke. If Nevada joined California the people of Nevada would need to help pay debts they had no part in creating. A number of California retirees receive much larger pensions than their equivalents in Nevada. The people of Nevada would not want to pay them.
There are no states between California and Nevada.
California is the American State to the left (West) of Nevada.
Nevada
Nevada borders California to the west. Sacramento is the capital city in the U.S. state of California.
California
Mainly California, though I believe it touches into Nevada.
The California Gold Rush brought people to the state.
Lake Tahoe is on the state line between California and Nevada.
Nevada