Last week, we reported that President Obama had lagged behind Bill Clinton and George W. Bush in making presidential appointments. Part of the holdup can be attributed to Republican opposition, but it’s also a function of the fact that the president has so many darn spots to fill — more than 1,000. A few of the more obscure ones:

• Utah Reclamation, Mitigation and Conservation Commission: The commission, created in the mid-1990s, is charged with offsetting the environmental impact of various federally funded water projects in Utah. The president appoints five commissioners, according to the Plum Book. By law, all of them must be Utah residents, though they don’t require Senate confirmation.
• Morris K. Udall and Stewart L. Udall Foundation: The president appoints the nine trustees of the foundation, which does work on environmental policy. The nominees need to be confirmed by the Senate, but they’re considered through a special expedited process set up in 2011.
• Marine Mammal Commission: The president appoints three commissioners, who need to be confirmed by the Senate. The commission helps protect — you guessed it — marine mammals.
• Railroad Retirement Board: The board administers retirement benefits for the nation’s railroad workers. The president appoints its three members as well as the board’s inspector general, all of whom require Senate confirmation.
• Barry Goldwater Scholarship and Excellence in Education Foundation: The foundation awards scholarships to students intending to pursue careers in math, science and engineering. The president appoints its eight board members, who are considered via the expedited process.

The number of presidentially appointed positions has been climbing for decades. As Congress has created new agencies like the Department of Homeland Security, it has added new presidential appointments, which often required Senate confirmation. But as we reported, dozens of appointed positions at agencies from the Defense Department to the Office of Government Ethics are now sitting unfilled.

Still, many of the more modest of the appointments — like the ones to the Udall Foundation — aren’t controversial and don’t take up much White House time, said Cal Mackenzie, a Colby College professor of government who has studied the politics surrounding presidential appointments since the 1970s.

There’s also a potential upside to having the president appoint board members to minor boards and commissions, said Anne Joseph O’Connell, a law professor at the University of California, Berkeley, who has studied presidential appointments. The positions are often part-time and don’t pay much. But if appointees get a call from the White House, O’Connell said, they might be more willing to serve.