Farmington

From 1924 to 1943, Stevens and his family lived on 725 Farmington Ave in West Hartford. This thoroughfare actually joined Hartford with the city of Farmington, CT to the west. 
Stevens mentions the town once in his poetry. The references occurs in “The River of Rivers in Connecticut,” published in The Rock (1954).  Here are the lines:
The river is fateful, 
Like the last one. But there is no ferryman. 
He could not bend against its propelling force.
It is not to be seen beneath the appearances 
That tell of it. The steeple at Farmington 
Stands glistening and Haddam shines and sways.
We should not take the lines literally, since about 30 miles separate the towns of Farmington and Haddam—thus an observer could not simultaneously see Farmington glistening or Haddam shining. (According to “13 Ways of Looking at a Blackbird,” Haddam contains only “thin men,” undercutting its ability to shine or sway.)
The “river of rivers” might be a reference to the Connecticut River, called the “great river this side of Stygia” in the poem. A section of the Connecticut crosses the mid-way point between Farmington and Haddam at a small city called Middleton. Stevens’s poem never refers to Middleton specifically, however.
==AN Alternative View==
In the above interpretation, the "river of rivers" is the Connecticut River. According to the map above, the Connecticut is the only river where an observer might theoretically see both Haddam and ​Farmington (although the distance between them is 30 miles). In addition, the Connecticut River would be the "river of rivers" for that particular state. Under this view, the "Farmington" referenced in the poem is clearly the city of Farmington.
In a Voices and Vision article on Wallace Stevens, however, Helen Vendler suggests the "river of rivers" is actually the Farmington River. This river is west of the city of Farmington, curves eastward as it flows north, and flows into the Connecticut river north of Hartford. Vendler believes it likely that Stevens knew this route well. The problem with such a view, however, is that since the Farmington River is actually west of Farmington, it is actually much further away from Haddam. Thus it is more unlikley that any observer could seeing Farmington's steeple shining and Haddam shining and swaying.