A couple of weeks late, but the the pumpkin plant is finally in the ground. I put the green house on it with a 60-watt bulb to keep it warm last night. We are now officially off and running!
To plant your pumpkin you should mound your prepared soil (soil preparation is talked about below) so it looks like Table Top Mountain. The top should be a couple of inches higher than the surrounding soil. Plant your pumpkin a few inches from the edge of the mound with a little mycorrhizal fungi in the hole where the roots will be touching. This will give you more area for the sun to warm the soil around the pumpkin and help it get a good start during cool Colorado spring nights.
Don't be afraid to put some dirt under the vines to support them as the plant transitions to its new home.