Start from Dead Dog Well, cross the arroyo and climb 300 ft to the top of the Caja del Rio. This trail starts with an easy grade and gets steeper from there.
There are some tricky step-ups and switchbacks, but, overall, it is manageable for an intermediate rider. At the top, you'll be rewarded with killer views back towards the Sangre de Cristos. From the top you can continue on and explore the Caja del Rio plateau which is criss-crossed with trails.