This looks like another thread worth reviving for 'woodland week'.
To answer the original poster - depending where you are located, a good stand of Lodgepole Pine is a bit of a rarety. I have a small number dotted around and they are not intended to be part of any future cull or thinning. The very first thing I would do (and have done on my place) is to get rid of ALL the white fir species (e.g. Grand Fir). They are prone to bark beetle and
root rot, are not worth much at the mill and tend to take up room that could be used for a better tree, until they die early or blow down.
I would then hire someone with a skid steer and forest grapple to pull out all the brush (and burn it - or if you want to spend the money, hire a large chipper/shredder and mulch the brush), so I could see what I have to work with. Next step would be to do a thorough survey of the remaining stand, mark any trees with bark beetle sign and cut those down. To be on the safe side, you might want to burn any logs with bark beetle - but we successfully stacked them, tented over the pile with thick plastic and let the summer sun bake the beetles instead. I've also read that people use strong aromatics to paint some of the logs, which creates a toxic atmosphere under the plastic to make sure the beetles are killed off. There is a lot of hype (some of it justified) about beetle infestation - but read up from legitimate forestry sources.
While it's tempting to go straight into digging swales, you can create the conditions to start sinking runoff, and capturing silt from the runoff, using log lines on contour as an alternative to
berms. You probably also have lots of partly rotted branches lying on the ground. Again, it might be tempting to get rid of those, but if instead you lay them just uphill from your 'log berms' it can generate soil more quickly. From the description of the site, you are likely to have lots of trees that you can pick out for culling due to them being crooked, double trunked, etc that can be specifically felled for your log line. Getting a log line to stay put, if you can identify cull trees conveniently placed to yield stumps that can hold the log line on contour, that would be useful.
Try to relook at the site as having useful resources that can be harvested and used rather than going straight for full scale flattening and landscaping. Observation in between steps gives time to reconsider all options along the way. Also, if you want to retain any trees on your site - try to not cut more than a regularly distributed 20% in one year. Trees support each other from the winds and need time to regrow and strengthen back up when one of their buddies is harvested. There are lots of examples in lightly forested areas where the wind takes out a tree, and then several fall like dominos in the wind's path, because they no longer have the protection from the first tree to go down.