The Sierra Club endorsed state Sen. Eric Griego in the Democratic primary for New Mexico’s open 1st district.

The group has 8,000 members in its Rio Grande Chapter, which voted unanimously to endorse Griego over former Albuquerque Mayor Marty Chavez and Bernalillo County Commissioner Michelle Lujan Grisham.

All three are hoping to replace Rep. Martin Heinrich (D), who is running for Senate. Two Republicans, Albuquerque City Councilman Dan Lewis and former state Rep. Janice Arnold-Jones, are currently in the race, while 2010 nominee Jon Barela is considering another bid.

The New Mexico Politics blog reported that Army veteran Gary Smith (R) will also jump into the race and plans to seed his campaign with “a couple hundred thousand of his own cash by the end of the year.”

The traditionally Republican Albuquerque-based district will be altered in redistricting, but that process is currently in the courts.