A second lightning-sparked fire is burning in the Rincon Mountains east of Tucson.

The Jackalope Fire was first reported at about 2:30 p.m. Thursday in Saguaro National Park's Rincon Mountain District. It is located on Tanque Verde Ridge, near Juniper Basin.

The wildfire is burning in grass and juniper at an elevation of about 6,000 feet. It is estimated to be about 10 acres as of Thursday evening, according to a news release from Saguaro National Park.

The Tanque Verde Trail from the trailhead at Javelina Picnic Area to Cow Head Saddle is closed, as is the Juniper Basin Campground.

There are no structures threatened, however, the wildfire will be fought to protect nearby Sonoran desert vegetation, park officials said.

Meanwhile, the Deer Head Fire in the Rincons has grown to more than 750 acres.

That blaze, started by lightning a week ago, is being managed to benefit the environment and to burn off ground fuels like grass, pine needles and fallen trees. It is burning among ponderosa pine, oak and brush at elevations ranging from 7,000 to 8,400 feet.

Crews have been assigned to the fire to make fire lines and conduct burnout operations to help manage the fire.

For information about campground and trail closures associated with these fires go to the park's Facebook page.