Cultural institutions in Los Angeles sometimes bemoan the difficulty of cultivating generous donors who will help fund their operations. Over the last few years, the art collector Jarl Mohn, 72, has emerged as an exception.

He and his wife, Pamela, 71, recently gave 260 works from their collection of Los Angeles artists to be shared by three museums — Los Angeles County Museum of Art (LACMA), the Hammer Museum and the Museum of Contemporary Art, Los Angeles (MOCA). The gift also came with a $15 million to $20 million endowment for new acquisitions and expenses, in part so that works can travel to museums in other cities.

Last June, the Brick — the nonprofit visual art space formerly known as LAXART — opened its new home on Western Avenue in Melrose Hill, thanks in large part to a $1.25 million gift from the Mohns (although the couple gives jointly, Jarl is the driving force behind their collecting).

Last May, the Mohns gave the Institute of Contemporary Art, Los Angeles museum a $4.4 million naming gift that will almost single-handedly pay for the museum’s renovation downtown

The Mohns have also established a grant program through the Los Angeles Nomadic Division (LAND), which gives up to 20 emerging Los Angeles artists $5,000 each over five years — along with curatorial and production support — to help them create their first significant public presentation in Los Angeles County.

And since 2012, they have underwritten the Mohn Awards, which honor artistic excellence, in conjunction with the Hammer Museum’s important biennial exhibition, “Made in L.A.”