Opportunity is on the west rim of Endeavour Crater near the entrance of "Marathon Valley," a putative location for abundant clay minerals.

The rover is positioned on a light-toned outcrop next to the feature called "The Spirit of St. Louis" crater. The rover is continuing a campaign to investigate surface targets in this outcrop.

On Sol 3984 (April 9, 2015), Opportunity examined the surface target called "Thermopylae" using the robotic arm to collect a Microscopic Imager (MI) mosaic and later perform a placement of the Alpha Particle X-ray Spectrometer (APXS) for a multi-sol integration. On Sol 3986 (April 11, 2015), the rover repeated this set of science observations on a different target within the rover's work volume.

Another MI mosaic and APXS integration were collected. On Sol 3989 (April 14, 2015), Opportunity bumped about 24 inches (60 centimeters) to position to reach some other surface targets in the same outcrop. The rover has implemented a supplementary way of collected additional battery data and has also been acquiring some atmospheric opacity measurements to support the Insight mission.

The rover experienced two more amnesia events on the evenings of Sols 3987 and 3988 (April 12 and April 13, 2015). Both were benign and resulted in no loss of science data. The rover is otherwise in excellent health.

As of Sol 3989 (April 14, 2015), the solar array energy production was 561 watt-hours with an atmospheric opacity (Tau) of 0.813 and a solar array dust factor of 0.714.

Total odometry is 26.24 miles (42.24 kilometers), more than a marathon.