The British Geological Survey (BGS) said the quake happened just after 7.35pm on Thursday and was reported by almost 200 local residents.
Almost all of them came from within a 12.5 miles radius of the epicentre which was just over six miles to the west of Fort William and two miles south of Loch Eil.
Many described the impact as moderate, with windows rattling and a loud rumbling that sounded like thunder. Several also stated that their houses shook.
Residents from Glencoe, Oban and Lochaber also felt the tremors.
Julian Bukits, assistant seismologist at the BGS said " At 2.9 on the scale it was average in the UK and insignificant in global terms.
"In December 2005 there was an earthquake with a magnitude of 3, less than two miles to the east of this most recent one. The most significant earthquake in the UK registered 5.4 in 1984 on the Lleyn Peninsula in North Wales."
Fort William and Ardnamurchan local councillor Andrew Baxter was one of those to feel Thursday's tremor. He said: "We weren't sure whether it was a large lorry going past or a clap of thunder.
"I wouldn't say it was frightening, confusing more than anything. I was in quite a rickety old village hall and it certainly shook for the few seconds it lasted."