Geyserville and nearby Alexander Valley are in line for road and bridge improvements leading to River Rock Casino.
More than a mile of Geyserville Avenue will be repaved in coming months with $200,000 secured from federal funds set aside for roads to Native American lands or businesses.
Another $150,000 has been obtained to kick off engineering and environmental studies on the Highway 128 bridge over the Russian River near Jimtown, to bolster the span's abutments.
Hundreds of cars and about 30 tour buses use those roads daily to bring 1.3 million visitors annually to and from the casino on the Dry Creek Rancheria, about four miles from Geyserville.
North County Supervisor Mike McGuire said the use of the specially designated funds is new on the North Coast.
"This is the first collaborative project that will be getting off the ground north of the Golden Gate Bridge utilizing the Indian Reservation Road Fund," he said.
The Dry Creek Rancheria Band of Pomo applied for the money as part of a joint partnership with the county, McGuire said.
Tribal Chairman Harvey Hopkins said Friday that even though the money is being used on the most traveled routes to the casino, "this is not a mitigation issue. It's an an opportunity to share a grant the tribe receives with the county."
He said the Federal Highway Administration allocates the money for roads that tribes use.
"It doesn't have to be going to the casino. It could be going to the (tribal) office in Santa Rosa," he said.