When I visited Donna Olsen, my cousin in Riverton, WY, she took us to Martin's Cove. (This was before the visitor center.) She also took us to the Riverton Stake Center and copied a bunch of materials for me--stories and minutes with regards to the Martin and Willie Handcart Companies; first and second rescues. I was left with a big packet of materials, including short synopsis Isaac's life, a day-by-day account of the Handcart Company and their rescue after they hit the snow. This includes journal information. It keeps the Martin and Willie Companies separate, while telling the story of where each company was on a particular date.
This packet also included information of the second rescue, which resulted in over 4000 temple ordinances being done. Many of the pioneers had passed away, and their temple work had not been done. This included baby Sarah Anne Ashton, who was born on the trek, and lived a couple of weeks only. This included dedicatory prayers, firesides, minutes of a special stake wide sacrament meeting, other interesting materials.
I used this material mostly when I wrote the musical, but have enjoyed the talks and prayers around the dedication of the monuments.