These are near Horsethief Butte. Horsethief Lake is said to cover an ancient Native American village nearly 3,500 years old. Some of these petroglyphs/pictograms were finally relocated here after they were moved due to The Dalles dam being constructed. Unfortunately it took many years for that relocation to occur. In that time they suffered a lot of damage due to poor storage methods.
There are other unmoved petroglyphs that can be seen on a guided tour that requires a free pass.