Steep washboarded gravel in the lower section gets the blood flowing, then a long dirt grinder with some rocky sections that are fine to ascend on a gravel bike ( or maybe a road bike you don't like very much ). The return is fast on paved Hyde Park Rd, and completing the loop on asphalt through Tesuque makes for a 32 mile loop with relatively low traffic and 4000 feet total elevation gain. Or bounce your way down whence you came.