The milelong hike to the tip of Bateman Island can reward hikers with breathtaking views of Rattlesnake Mountain and the confluence of the Yakima and Columbia rivers.
The way people get to the island could change, however. A study is looking at the 73-year-old causeway connecting the island to the riverfront trail in Richland.
The Mid-Columbia Fisheries Enhancement Group, a White Salmon-based nonprofit seeking to increase the salmon and steelhead trout population, wants to know whether the causeway is acting as a barrier to salmon migration.
The fisheries group and the Benton Conservation District have hired Intera Inc. of Richland to conduct computer modeling. The study, expected to be completed next spring, is part of the Yakima Delta Project.
If the causeway needs to be altered, culverts might be dug to let water through, or the water could be spanned with a new bridge, said Rebecca Wassell, Mid-Columbia Fisheries Yakima Basin program manager.
"There's probably a range of ways we could do it," Wassell said.
Aerial photographs of the land bridge show the murkier, warmer, water from the Yakima River on the west side juxtaposed with clearer Columbia water in the cove to the east. The calm area to the east is a popular summer hangout for boaters and fishers.
The fisheries group points to an August 1997 flight about the lower Yakima commissioned by the Bureau of Reclamation that used infrared technology and showed the Bateman Island causeway contributing to high summer water temperatures by stopping flow on the south side of the island. That report said the causeway reduces the area where the Yakima water mixes with the cooler Columbia water.
Water to the west of Bateman Island tends to back up, making it particularly hot, Wassell said.
"It's stagnant water," she said. "It collects energy from the sun and warms up more than any water around it."
The Yakima River historically has played host to runs of steelhead and different varieties of Chinook salmon, as well as coho and sockeye, according to a Mid-Columbia Fisheries summary of the Yakima Delta project.
Young fish migrate from the Yakima into the Columbia and return as adults. But a "thermal barrier" has been created at the delta, which is a particular concern for species including sockeye and summer and fall Chinook that migrate later in the summer, the report said. In addition, it creates a habitat that welcomes predators such as catfish and bass.
The Yakama Nation also is working on the project to study the presence and absence of fish species in the area.
Bateman Island is owned by the Army Corps of Engineers and leased to the city of Richland.
The study also is looking at the effect changing the causeway could have on the marina to the east, as well as recreation on and around the island, Wassell said.
The process will include an opportunity for the users of the area to speak about any proposed changes.
"We are not trying to freak anybody out," she said.
The cost of altering the causeway hasn't been determined, Wassell said. Getting an estimate is part of a planned conceptual design of the project. Mid-Columbia Fisheries is seeking grants from the state Salmon Recovery Funding Board.
Corps spokesman Bruce Henrickson said the agency received a proposal on the Yakima Delta Project from Mid-Columbia Fisheries on April 29. The agency must decide, for one thing, if it has the authority to modify the causeway.
"We get lots and lots of proposals from lots and lots of outside partners," he said. "We just have to review them and decide where we might be of assistance."
A lengthy process could follow before the Corps approves changes to the island. Henrickson compared the process for any modifications to the causeway to the National Environmental Policy Act review that was required to build the nearby Hanford Reach Interpretive Center on Corps-managed land in Columbia Park.
"That proposal's environmental review process involved dialogue with local entities, state and federal agencies and Indian tribes plus assessing project compliance with eight federal laws, two federal executive orders and three Washington state laws and permits," he said. "Such review work is detailed work, and we do it well, following all applicable laws."
Because of federal sequestration cuts, Henrickson said the Corps likely would need help from outside sponsors if it had to alter the causeway.