Disk "materializes" in vertical position in the sky, 225 Ft. from me, then manuevers to horizontal position and descends behind hill

It was a moonless night about 9:15 pm. I was camping at Lost Lake Recreation Area. I sat by the San Joaquin River, Looked up and saw a "ribbon of light" vertical in the sky. It was dark grey in color, and materialized 225 ft. from where I sat at a picnic table which was about 2 ft. from the water, on the Fresno County Side of the San Joaquin River inside Lost Lake Recreation Area. The disk was on its side, vertical, when it appeared. It then manuevered itself into a horizontal position. There was a row of lighted windows around the entire craft. It made no noise and it descended behind a hill on the Madera County side of the San Joaquin River on land that is owned by the Water Reclamation Bureau, the northern most point of the strip of land is just south (below) the Friant Dam, and runs south, the length of the San Joaquin River. And, running alongside the government land, are grape vineyards owned by a private party. The name of the private road running adjacent to where the craft appeared to descend is Bureau Road. I did not have my cellphone with me.