Thank you for your question about your Ponderosa pines turning brown plus  lesions on some of the branches.  It looks like you have some abiotic (not derived from living organisms) diseases affecting your trees.  The natural Ponderosa habitat is exposed hillsides, mesas, and south-facing slopes.  Ponderosas are drought tolerant and require infrequent irrigation.  Soils should be well drained, sandy or gravelly.  The native life zone for this tree is foothills/montane.  Your trees may be stressed because of the location, out on the plains, growing in less gravelly soil with poor drainage.

https://coloradoplants.jeffco.us/plant/details/757

https://extension.usu.edu/rangeplants/shrubs-and-trees/PonderosaPine

Your trees could also be experiencing, ‘Winter Damage of Evergreens (Frost, Winter Burn, and Winter Drying’).  I have attached a couple of pages from our book, ‘Insects and Diseases of Woody Plants in Colorado’.  Please take a look to see if the pictures and descriptions match what is happening to your trees.  “Needles may turn yellow, red or red-brown from the outside inward.  Entire branches may yellow and brown from the outside inward. Usually current-year needles are the most severely affected.”  Management includes watering evergreens approximately monthly in the absence of adequate snowmelt or rain fall (November through March).

Late October 2019, our area experienced a severe cold snap during warm fall weather.  Many of our eastern Colorado trees were unprepared for this sudden drop in temperatures and had not gone dormant for winter protection.  This event may have caused damage to your trees.

https://csfs.colostate.edu/2015/03/04/colorado-trees-showing-damage-from-fall-freeze-winter-scorch/

The lesions on the branches may be caused by a biotic disease, Stem Decay Fungi, which entered the tree through a wound.

https://wiki.bugwood.org/HPIPM:Stem_Decay_Fungi_of_Hardwoods_and_Conifers

I have included a Tree Service Reference List in case you would like an arborist to come look at your branches and provide recommendations about how manage the branches with decay.

https://colorado.volunteersystem.org/users/documents/9Tree_Referral_List1306.pdf