The Passumpsic River flows southward through the center of town. Near the southwest corner of town, the Moose River feeds into the Passumpsic from the east and the Sleeper's River flows in from the west. Nichols Pond is located in St. Johnsbury.
The hills of St. Johnsbury are all 1500' or lower: Saddleback, Mt. Pisgah, Hooker Hill, Bible Hill, Crow Hill and The Knob.
The early settlers made use of the abundant waterpower to operate many different industries: sawmills, gristmills, starch factories, tanneries, foundries, hemp works, woolen mills, a fork and hoe factory, and the Fairbanks Iron Works which manufactured plows, stoves, carriages and the world-famous platform scales. The settlers also gathered sap from the maple trees for syrup and, in the early 1900s, maple products became an important industry.
In 1971 the Carl Lawrence Farm was given the Century Farm Award. The award acknowledges 100 years or more of ownership in the same family. John Ide, great, great, great, and grandfather of Carl Lawrence settled the land in 1792. Other members of the family were founders of the first Grange in Vermont.
St. Johnsbury is the site of the largest and most continuous esker in the region. An esker is a long, low, typically sinuous ridge of sand and gravel deposited along the course of a stream that tunneled through a wasting ice sheet. The oldest and most beautiful section of the town, the Plain, is on the crest of the esker and US Rt. 2 descends its steep flank along Eastern Avenue. The materials and cross sections of the esker are exposed in a sand and gravel pit at the south end of Main Street. Several other quarries operate along its 24-mile length along the Passumpsic to the north. Clear, clay-free materials of eskers are excellent for concrete and asphalt aggregates, roadbeds and other construction uses.