This is another beautiful Oklahoma State Park. To get to campgrounds, turn off U.S. Highway 60 onto State Highway 137. This road runs through the park with campgrounds on either side of the highway. We were worried about road noise during the night but traffic declined sharply after dark. We stayed at Echo Hollow campground on the east side of Highway 137 overlooking Spring River. We were in a shaded site with a good view of pelicans on the river. We will come back here when we have more time to spend so we can explore the area and fish from the enclosed fishing dock. I checked yes for big rigs as our motorhome is 38 feet and we fit in a site just fine. We had no trouble getting level. We camped here in a Motorhome.