Near Bear Valley in Mariposa County, California — The American West (Pacific Coastal)
May Rock
Photographed by Barry Swackhamer, August 18, 2011
1. May Rock Marker
Originally named Tower Rock, May Rock is the largest outcropping of quartz along the Mother Lode. This 82 foot high formation contains no gold ore. Most gold ore within quartz is at greater depths in the earth.
It was part of Colonel John C. Fremonts 1847 Las Mariposas 44,000 acre land grant and later owned by Louis Trabucco.
To celebrate May Day, people came from Bagby, Bear Valley, Elkhorn, Hornitos, Mariposa, Quartzburg, and Princeton.
It became the central gathering place on May Day for picnics, races, music and a May Pole dance.
Jessie Fremont was an early organizer of these events and bestowed the name May Rock, in remembrance of a May Day picnic here.
May Rock is currently owned by Robert Bondshu, a descendant of the pioneer Bondshu, Hope, Halstead, and McGregor families of Mariposa County.
Erected 2010 by E Clampus Vitus, Matuca Chapter No. 1849.
Topics and series. This historical marker is listed in this topic list: Natural Features. In addition, it is included in the E Clampus Vitus series list. A significant historical year for this entry is 1847.
Location. 37° 32.741′ N, 120° 5.796′ W. Marker is near Bear Valley, California, in Mariposa County. It is on State Highway 49, on the
this page online
Regionally, this marker is in California’s Gold Country and in the Sierra Nevada. It is also in the American Mountain West. Globally, it is in North America, the Pacific Rim, the Western Hemisphere, the Western World, and the Anglosphere. Historically, it finds itself in what was once New Spain and also Mexicos Alta California.
Other nearby markers. At least 8 other markers are within 5 miles of this marker, measured as the crow flies: Gertrude School (approx. 1.8 miles away); Bear Valley (approx. 2 miles away); a different marker also named Bear Valley (approx. 2 miles away); Mrs. E. Trabucco Store (approx. 2.1 miles away); Mount Ophir Mine (approx. 2.7 miles away); Fremonts Fort (approx. 3.3 miles away); La Mineta 1850 - Princeton 1854 - Mount Bullion 1862 (approx. 3.9 miles away); Bagby (approx. 4.9 miles away). Touch for a list and map of all markers in Bear Valley.
Another marker is no longer nearby. Mount Ophir Mines (was approx. 2.7 miles away but has been replaced with another marker now near it).
Photographed by Barry Swackhamer, August 18, 2011
2. May Rock Marker
May Rock is seen in the background.
Photographed by Barry Swackhamer, August 18, 2011
3. May Rock
Credits. This page was last revised on May 29, 2026. It was originally submitted on August 22, 2011, by Barry Swackhamer of Brentwood, California. This page has been viewed 2,481 times since then and 103 times this year. Last updated on May 29, 2026, by Liam Williams of Irvine, California. Photos: 1, 2, 3. submitted on August 22, 2011, by Barry Swackhamer of Brentwood, California. • Devry Becker Jones was the editor who published this page.
