Samuel Montague's engineering report of 8 October 1864, under ALIGNMENT, states "Although by Act of Congress . . . you are allowed to use the maximum curves on the Baltimore and Ohio Railroad, the adopted maximum is ten degrees, or a radius of five hunddred and seventy-three feet." (The Act of Congress referred to is that of July 2, 1862, I believe the curve issue is in section 13.)
The implication in Montague's statement is that the B&O's curves were sharper ("maximum" in Montague's statement referring to the highest degree curve allowed) than the 10-degree curve standard adopted by the CPRR. In fact, there was one (or more likely, one reverse) mainline curve of 14 degrees in Palisade Canyon, opposite the mouth of Pine Creek, just west of Palisade station. The commissioners found no reason to complain about this curve (had they noticed it?). Was it within the Act's limit? Nowhere do I find a definition of the B&Os tightest curve as of 1862 (I do find an 18-degree curve on the B&O as of 1833).
That 14-degree curve was removed by July 1869 by relocating the Humboldt River, so it was probably always considered temporary.