Building on the work of Dr. Howard Tipper and Dr. Louise Longridge, along with Taylor et al from 2001, Pengfei Hou did a Master's thesis through UBC in 2014 on Sinemurian (Early Jurassic) stratigraphy at Last Creek, British Columbia and Five Card Draw, Nevada : paleontology and environmental implications.
As part of that work, he collected over 400 ammonite specimens from the Last Creek Formation in Last Creek, British Columbia and the Sunrise Formation in Five Card Draw, Nevada. The research led to three new species: Tipperoceras n. sp. A, Tmaegoceras obesus n. sp., Arnioceras n. sp.
The two gastropods you see in the central block look to be Promathildia turritella. The age is certainly correct. Here's hoping a nice grad student takes an interest. The rare but lovely gastros from this area would make an excellent thesis. Perhaps comparing their distribution to their counterparts in Europe.