As I said, this is a great trail to make a great point to point or lollipop or just out and back.
Option #1: Instead of turning right at the junction that takes you to the Colorado Trail, don't turn, just keep going straight and you'll have done an extended Coalbank Pass to Molas Pass
Option #2: Before meeting the Colorado Trail on the Engineer Mountain Trail you'll look to your right and see a nice little mountain known as Jura Knob. There is no trail but it is a nice little scramble to the top for a little more elevation gain and view.
After you meet the Colorado Trail, there are several lakes and streams where you can filter water if you don't want to carry all day water supply.
I have not completed the portion of the Engineer Mountain Trail that starts at the bottom of Coal Bank Pass, so this description will only cover where you intersect the Pass Creek Trail
on your way up to Engineer Mountain. The portion of the trail beginning near Coal Bank Pass is a moderate incline, though there are some steeper portions. Along the way, the trail will pass through meadows and dense forest alternately, eventually ending at the Colorado Trail.
From the intersection with the Pass Creek Trail
, either go up Engineer Mountain (left), down to Coalbank Pass (right) or continue on straight. After roughly a mile, you'll come to an intersection, go left to continue on the Engineer Mountain Trail. Going right will take you towards the base of Jura Knob. The views of the knob are beautiful, and this is a good place to take photos or just to appreciate the view.
In another 1.8 miles, you'll come to yet another intersection. To stay on the Engineer Mountain Trail, turn right and steeply ascend the trail to connect with the Colorado Trail after about 1.5 miles. It is my understanding that this is technically the end of the Engineer Mountain Trail.
If you continue on at the junction, turn right (keep going straight) and this will eventually lead you to Molas Pass.
The region has abundant Alpine beauty, with marmot, pika, and alpine wildflowers.