Egg Rock is usually accessible using foot trails over land, but during high river levels the island is separated from the mainland by a narrow channel.

In the GNIS database as of February 2010, the listed position (latitude 42.4645383, longitude -71.3592266) is misplaced by about 125 meters to the southwest, and is not actually located on the intermittent island.

[3] An inscription was carved into the rock in 1885 to commemorate the 250th anniversary of the 1635 founding of Concord:[4] On the hill Nashawtuck at the meeting of the rivers and along the banks lived the Indian owners of Musketaquid before the white men came The significance of the inscription would have been clear to most people familiar with local lore at the time it was carved, although it may seem cryptic now to many people who are unfamiliar with Concord's history and geography.

The principal local settlement of the Massachusett tribe which remained in 1635 (after various European diseases devastated the original population in the preceding two decades) was nearby on the gentle slopes of Nashawtuc Hill,[6] whose crest is about 500 meters southwest of Egg Rock.

Negotiations initiated by Simon Willard with leaders of the tribe gave English settlers the right to live in the area, which came to be called "Concord" in appreciation of the peaceful acquisition.

As Charles Hosmer Walcott, chairman of the Tablet sub-committee, declaimed in a speech he delivered during the Sept. 12, 1885 celebration, the seven memorials "form an epitome of the town's history for a century and a half—from the beginning of the plantation to the war of the revolution."

Concerning the inscription on Egg Rock itself, he continued: The simple words inscribed on the rugged face of the rock, where the rivers meet, will serve to remind us and succeeding generations of a people who have vanished from the face of the earth, leaving scarcely a trace of themselves, except a few arrow-heads and stone pestles, and, here and there, a mound or a heap of clam shells.

Egg Rock's location at the confluence of these rivers, and nearly in the center of Concord's land area, has resulted in its status as a notable landmark for many years.

[13] In the first stanza of his romantic 1875 poem “Floating Hearts,” George Bradford Bartlett considered Egg Rock among the major riverside vistas of Concord, alongside the Minute Man statue at the Old North Bridge and The Old Manse: One of Indian summer's most perfect days Is dreamily dying in golden haze, Fair Assabet blushes in rosy bliss, Reflecting the sun's warm good night kiss.

Through a fleet of leaf barques gold and brown, From the radiant maples shaken down, By the ancient hemlocks grim and gray Our boat drifts slowly on its way; Down past Egg Rock and the meadows wide, Neath the old red bridge we slowly glide, Till we see the Minute man strong and grand, And the moss grown Manse in the orchard land.[14][...]

"[19] Egg Rock has been the site of a winter solstice ceremony sponsored by the Emerson Umbrella Center for the Arts, which included a bonfire.

[20] It has served as the starting point for an annual fund raising event produced by the local Milldam Nursery School, in which nearly 2000 yellow rubber ducks float down the Concord River from Egg Rock to the Lowell Road boat launch ramp, about 300 meters downstream.

This segment runs through woodland about 1.5 kilometers to the northwest and about 200 meters to the east from the intersection; in both directions that trail ends at riverbanks where railroad bridges formerly stood.