Route 179's original location, defined in 1932, was an 11-mile trip from US 44 in New Hartford to Route 20 in Hartland, along the following route:
- today's Route 219, from US 44 to a short distance past Route 318
- East Road, continuing north to Walnut Hill Road in Hartland, which was the original alignment of Route 20 (see my map.)
Before the 1932 renumbering, this route was known as State Highway 204.
The opening of the Saville Dam on Route 318, and the flooding of the Farmington River to form the Barkhamsted Reservoir, led to significant changes in the area. Two villages – Hartland Hollow and Barkhamsted Hollow – were flooded. Route 179, Route 181 and Route 20 were relocated.
East Road, which served Barkhamsted Hollow and carried Route 179, followed the east bank of the Farmington River. Parts of it are underwater, but most of the roadbed is visible from the air, though it's no longer on maps or open to traffic. It might be open to hiking; however, since it encroaches on a supply of drinking water, it might not.
By 1941, the northern portion of Route 179 had been moved away from East Road, following E. Hartland Road all the way to North Hollow Road, which was the new path of Route 20. The new length of Route 179 was 10.98 miles.
In 1935, part of Gavitt Road in Hartland was added to the state system as SR 721. In 1940, SR 721 was extended a short distance southeast along North Canton Road. These segments would later go to Route 219 and Route 179.
In 1943, East Hartland Road and Granville Road, from Gavitt Road north to the Massachusetts state line, were added to the state highway system as SR 719.
In 1944, the south end of Route 179 was relocated along present-day Route 179, through North Canton and Canton Center, to end at today's US 44/Route 179 intersection. Route 179 was also extended north from Route 20 along Granville Road (replacing SR 719) to the Massachusetts state line, for a total length of 15.64 miles.
In 1963, Route 4 was relocated, and Route 179 was extended along former Route 4 to Burlington; at 19.73 miles, this was the the route's longest configuration.
On March 1, 1979, the northern terminus of Route 179 was pulled back to Route 20, and the remainder was renumbered SR 819: a state road, but no longer signed. This might have been done because the road across the state line is not a state road, leading to a "dead end" for the 179 designation at the Massachusetts border.