I have been going through the Church History Trail Excerpts for the Martin Handcart Company. These can be found at the church website LDS.org. http://lds.org/churchhistory/library/pioneercompanysources/1,16272,4019-1-192,00.html
I am finding their is a great deal to go through, but the process is worth it. However I have divided it into sections so I can keep track of where I have been. In this section there is an excerpt from Dan Jones' book. He was one of the rescuers and part of the express group that found the Martin Handcart Company. He was also selected to spend the winter at Devil's Gate to guard the goods of the Saints that were left so they could use the wagons to cart the pioneers.
There is a quote from one young man who noted that because some were sick, there was an added burden on others to carry them on their carts. Of great import in this section is the journal of Jesse Haven. He was captain of Company E from Iowa City to Florence. This company was combined with Company F at Florence to form the Martin Handcart Company. Jesse Haven then helped with the wagons. I am convinced that Isaac was in this company until reaching Florence. This is based on Langley's mother appealing to Captain Toone for a blessing for her son. Captain Toone was with the Haven group. He continues as a captain of 100 with Elder Martin.
These pages also give an idea of the weather. It went from in the 100s to below zero in a matter of a few months. It also describes the problems with the Indians this year. There were several attacks upon the plains, but they left the handcart pioneers alone for the most part. There is a gruesome story of a wolf attacking and eating a man just before the last crossing of the Platte. This seems to have made an impression on the pioneers.