In 1849 it was established from Sacramento to Auburn, Grass Valley and Nevada City and to-day there is practically little deviation from the original route.

In 1850 the mines on the Forest Hill Divide were discovered and a branch road from Auburn was built to that section.

At Illinoistown (now Colfax) the road branched, one arm crossing the North Fork of the American River to Iowa Hill and other camps on that divide, while the main road continued up the Sierras to Gold Run, Dutch Flat and other points higher up.
Until the Central Pacific Railway was built in the 'sixties Illinoistown was the junction for the different Camps in Nevada County and the Bear River and Iowa Hill Divides.

The population of these regions in those early days was much greater than at the present time, yet the demands of the modern automobile have so improved the roads that they are much superior to what the large population of those days enjoyed.
In 1862 the California legislature authorized the supervisors of certain counties to call special elections to vote upon the question as to whether those counties should subscribe towards the building of the Central Pacific Railway, and to authorize them to issue bonds for the amounts they decided to expend.

San Francisco county subscribed $1,000,000, Sacramento county $300,000 and Placer county $250,000.
In 1863 the Railroad Company began its work of grading the road bed at Sacramento, and yet, in 1865 it was only completed to Alta, a distance of 68 miles.