Boart Longyear marks its 125th anniversary with a display at the National Mining Hall of Fame and Museum in Leadville, Colorado, US.

The display includes a timeline and collection of Longyear and Boart Longyear artefacts, dating back to the late 1800s.

Kent Hoots, senior vice-president of Boart Longyear, said: "The display and historic pieces are proof of the long and respected legacy of quality and innovation that Edmund J. Longyear started in 1890 and that we maintain today."

All but a few of the historic pieces on display have been permanently donated to the museum. Among those on loan for the summer is Longyear's first-ever drilling services contract, dated May 19, 1891. The handwritten contract was with Mallmann Iron Mining Company and included sinking diamond drill holes in the Mesabi Iron Range of Minnesota.

Included in the permanent collection of donated pieces is an original San Francisco Chronicle newspaper story entitled "The World's Greatest Span", dated October 5, 1930. The article features a photo of a Longyear drilling crew working over the blustery waters of San Francisco Bay as they determined the exact nature of rock formations that would bear the weight of the proposed Golden Gate Bridge.

Several personal items formerly belonging to company founder Edmund J. Longyear's eldest son, Robert Longyear, who took over the family business in 1923, can also be seen on permanent display.

Several catalogues and marketing books used to showcase Longyear's drilling products and services during the early 1900s are also featured in the collection. Past and present Boart Longyear employees are able to gain free entry to the exhibition this year.