Clarence or Claire

This novel is about a young family on their way to their new home in Colorado from Ohio. They were wealthy, but they sold everything in Ohio to go to a new home that only Roger C. Andrews has seen. (the C is for Charles)
Roger bought a canyon from Barnaby Collins because he loved it so much. He was tired of all the work involved in being the owner of a big store in Ohio. As a lark, they were taking a covered wagon to their new home following spring into the mountains.
Roger is killed trying to save his wife from a rapist. Claire, the young widow with five children, kills the rapist by mashing his head in with a rock.
After the inquest and funeral, she is taken advantage of by an older couple with no children. They want her to be Hagar for Sarah. She and her children escape.
Claire is 28 years old, 5'10". Roger was 6'. She puts on Roger's clothes and her riding boots and becomes Roger C. Andrews, (but I go by my middle name, Clarence or Clare for short. She had been signing his name to all the checks for years.)
Her oldest daughter Virginia cuts her hair. It was below-the-waist auburn, now it is man-length auburn. The family continues to their new home. Claire becomes the older brother for her three sisters and two brothers because she doesn't look old enough to be their father.
Their new home is in Collins Canyon below Misty Mountain and the twin falls. The high falls is so high the water forms a mist that gives the mountain its name. The lower falls is only a few hundred feet high and falls into the head of the canyon and a beautiful pool of water surrounded by meadow and trees. The Misty River then flows through Collins Canyon, down the rapids, past Twin Falls City, and on through Triangle Valley.
George Royce, the rancher who owns most of Triangle Valley, has tried to kill Barnaby Collis for ten years so he can build a dam at the mouth of Collins Canyon and irrigate thousands of acres of land above the valley and be even richer than ever. So, of course, he makes plans for Clarence Andrews.
This is a very involved story with many characters and subplots.