100 years ago today, Willis Linn Jepson was exploring the Middle River in the San Joaquin Delta.

Here’s what he says about the trip:
Went to Middle River today with Prof. Gregg on invitation of J.A. Sanford of Stockton.We were met by Sanford, Brown of Stockton, Ollahan, an expert on produce from Stockton and a wholesaler, and Filcher (Roy Welton), class of 1906, Berkeley. It was a very beautiful day and we had a fine time in a launch cruising about the islands. The day was very brilliant and the willows still in foliage.

The scanned field books are pictured above (as is Jepson, in a photo from 1911).

Jepson’s field notebooks have been scanned and are available online here.

Do you want to help?

We would like to increase the accessibility of Jepson’s field books. Because the field books are handwritten, the contents cannot be indexed by the Web search engines. If users are willing to transcribe the pages, however, little by little a great deal of information will be made widely available and searchable. We have built some simple tools with which you can associate a transcription with a page, or accumulate key-words.  Already volunteers have translated over 4400 pages! There are transcription links at the bottom left and right of each field book image page. We invite you to help make Jepson’s observations available to the world.

Happy transcribing!

Thanks to our awesome archivist, Amy Kasameyer, for the idea and the images!

The Sacramento Splittail (Pogonichthys macrolepidotus) is a local species to the Sacramento-San Joaquin Delta system. Spilttail is a perfect name for this endemic fish. They have an over sized upper lobe of a caudal (tail) fin. Splittails have a silver olive gray back and can grow over 40 cm.

The Sacramento Splittail has been a hot topic in the delta ecosystem. In 2003 they were taken off the threatened species list even though some believed they should have been put on the endangered species list. With persistence from scientists and local agencies in 2010 the U.S. Fish and Wildlife service worked on a 12 month study. This study showed that there was no recent decline in the abundance or significant threat to the Splittails.  Findings did show a high spawning period during flood years and a low spawning period during dry years. “If future evidence suggests that these threats are contributing to significant population declines, the Service may propose the species for ESA protection.” 

Dissolved Pesticide Concentrations Entering the Sacramento-San Joaquin Delta from the Sacramento and San Joaquin Rivers, California, 2012-13.

Surface-water samples were collected from the Sacramento and San Joaquin Rivers where they enter the SacramentoSan Joaquin Delta, and analyzed by the U.S. Geological Survey for a suite of 99 current-use pesticides and pesticide degradates. Samples we


IRVINE, Calif., Sep 26, 2014 (GLOBE NEWSWIRE via COMTEX) New Western Energy Corp. (OTCQB:NWTR), an independent energy company engaged in the acquisition, exploration, development, and production of oil, gas and other minerals in North America, today announced it has signed an LOI to acquire majority control of Island Energy Partners, LLC ( IEP ). IEP owns oil and gas wells, leases, and completion tools and equipment. The properties, wells and completion equipment are located in the Rio Vista Gas Field in California. There are 15 producing wells of interest on leases comprising 1300 acres. New Western will be conducting due diligence which it expects to complete within the next 45 to 60 days. The Rio Vista Gas Field is a large natural gas field in the Sacramento-San Joaquin River Delta in northern California, adjacent to Rio Vista, California. Discovered in 1936, and in continuous operation since, it has produced over 3.6 trillion cubic feet (100 km) of gas in its lifetime, and retains

Longfin smelt, Spirinchus thaleichthys.

Longfin smelt is a local species of smelt native to the northern Pacific coast of North America. You can find these fish in the Sacramento-San Joaquin Delta. They are known for their long pectoral fins, a pair of fins located on each side just behind the gill openings, which reach almost to the pelvic fins. The upper jaw line reaches back towards the eye while the lower jaw projects in front of the upper jaw. Adult longfin smelt are typically 3.5-4.3 inches, but older females can grow up to 5.9 inches long!

The longfin smelt population in the Delta is separated from other longfin smelt populations by ocean circulation. This population is at a historic low and is therefore considered a threatened species on the California State level. Even though a study has concluded the need for this protection, there are other “higher priority” listings of species and it will be a little while until these species are put on the Federal Endangered Species list.

For an in-depth explanation of this longfin smelt study, watch this video.

Watch on alistinexoxo.tumblr.com

So this just happened. 🌲🌲🌲 #slowmo (at San Joaquin Delta College)