Opportunity is exploring 'Marathon Valley' on the rim of Endeavour crater, investigating outcrops for evidence of clay minerals. The rover is continuing to examine a previously trenched (scuffed) surface.

On Sol 4385 (May 25, 2016), Opportunity collected some more targeted Panoramic Camera (Pancam) 13-filter images and continued with an Alpha Particle X-ray Spectrometer (APXS) integration on the surface target.

Then, on Sol 4386 (May 26, 2016), Opportunity bumped ever so slightly (about 1 cm) in order to reach a particular yellow pebble in the trenched area.

The rover collected more targeted 13-filter Pancam images. And then on Sol 4389 (May 29, 2016), Opportunity used the robotic arm (IDD) to collect a Microscopic Imager (MI) mosaic of the yellow pebble and to position the APXS just above the pebble (since it was too small to make a contact placement).

More targeted color Pancam images have been collected over the subsequent sols.

As of Sol 4391 (May 31, 2016), the solar array energy production is 643 watt-hours with an atmospheric opacity (Tau) of 0.566 and a solar array dust factor of 0.738.

Total odometry is 26.59 miles (42.79 kilometers), more than a marathon.