Individual entrance fees would go from current cost of 10 USA dollars to 15, even to 30 US dollars, it says.
"We can not let the most popular and awe-inspiring national parks become places only for the wealthy".
Fee increases are expected to generate an additional $70 million in park revenue per year, according to the National Park Service. Motorcycle fees would rise to $50, while individual person/bike passes would rise to $30.
The letter has no legal standing to prevent fee increases, but Becerra and other state attorneys general did not rule out future legal action.
The attorneys general urged the Service to scrap the proposed fee increases and instead seek adequate funding from U.S. Congress and support existing bipartisan legislative proposals, such as the National Park Service Legacy Act, which would provide more revenues for national parks without increasing park fees.
Pradyuman murder case: Ashok was grief-stricken, deadened to confess, alleges family
Chopra was present in court on Monday during the bail hearing, and claimed police and school authorities had framed Kumar. Also on Tuesday, the Central Bureau of Investigation (CBI) summoned a relative of bus conductor Ashok Kumar on Tuesday .
In a government letter signed by all 11 attorney generals, they state that the national park services have not given a reasoned explanation for the proposed fee increase.
In addition to Yosemite, Joshua Tree and Kings Canyon National Park in California, fee increases would affect visitors at the Grand Canyon in Arizona, Glacier National Park in Montana and Yellowstone in Wyoming.
Other attorney generals who have joined Attorney General Becerra in the letter are the Attorneys General of Arizona, Maine, Maryland, Massachusetts, New Mexico, New York, Oregon, Rhode Island, Washington, and the District of Columbia.
The NPS argues a fee hike is needed to address the agency's maintenance backlog, valued at $12 billion. The new deadline is December 22. It is not known whether the same thing would happen if fees are raised again.
Federal parks officials announced the proposed fee hikes in late October as part of a proposal to raise money to fix roads, bridges, campgrounds and bathrooms.