PHOENIX — Ever since their father became president, the Obama daughters, Malia and Sasha, have for the most part been seen but not heard.

But on a family trip to the Grand Canyon here Sunday, the voice of Malia Obama, 11, was crystal clear over the television microphones, as she demonstrated her acumen in geology to her very impressed mother and father.

The Obamas — President Barack Obama, his wife Michelle, their daughters and other assorted relatives including the president’s niece Suhaila Ng — received a tour of portions of the South Rim of the canyon from two interpretative park rangers. The tour was private, or at least as private as it could be with a pack of reporters along.

The family followed the rail of the South Rim along Hopi Point, elevation 7,071 feet, where the rim overlooks a 5,000 foot drop. Looking over the vista, with its dramatic view of a red rock butte and a big bend in the Colorado River down below, the president remarked that Malia wanted to know why the tops of the canyon were so perfectly straight.

“There used to be 3,000 feet of sediment up there,” one of the rangers, Scott Kraynak explained, adding that since the Obamas could not make the hike down to the bottom of the canyon, “I brought the bottom up to you.”

Kraynak produced some rocks, and showed Malia and Sasha, 8, his samples. This brought on a fatherly prodding from the one-time law professor-turned-president.

“You just studied this, right?” Obama asked Malia, who will enter the sixth grade at Sidwell Friends School in Washington in the fall. “What kinds of rocks are there?”

“There’s a kind of rock that’s made out of lava, right?” Malia replied. “Now what is that?”

“It starts with ‘I’,” the park ranger injected.

“Igneous rock,” Malia declared. She went on to name the other types of rock, sedimentary and metamorphic, without further coaching.

“High five!” Michelle Obama exclaimed, raising her hand to catch her daughter’s palm, mid-air.

Obama, who last visited the Grand Canyon was when he was 11, Malia’s age, put his arm around his daughter and squeezed, beaming.

MONTANA MISPEAK

All presidents like to get out of Washington, and all presidents like to poke a little fun at Washington when they do. But Obama’s speechwriters were apparently a little too funny for the president, who could barely get through his standard “it’s great to be out of the capital” shtick before a crowd in the big sky country of Belgrade, Montana.

“It’s nice to take a break from the going-ons in Washington,” Obama said as he read from the teleprompter, in an example of presidential misspeak that is unusual for him. “I’m thrilled to have a chance to spend some time with the folks in this beautiful state. After all, here in Montana you’ve got bears and moose and elk. In Washington” - and here the president stopped himself, laughing so hard it was momentarily difficult for him to continue — “you just have mostly bull.”

A FISH STORY

With false rumors about “death panels” plaguing Obama’s health overhaul initiative, the White House Web site is asking Americans to be on the lookout for chain-e-mails and to report back on information that “seems fishy.” But during Obama’s trip through the American West this weekend, another kind of “fishy” kept coming up — the one that got away.

Obama, while athletic, is not exactly a great outdoorsman in the mold of, say, his distant cousin, former Vice President Dick Cheney. Perhaps that was the reason photographers were not allowed to accompany him when he tried his hand at fly-fishing for the first time in Montana’s Gallatin River.

Or perhaps it was the memory of the time Obama tried another new sport, bowling in front of the cameras during his presidential campaign, and wound up humiliated with a score of 37.

Obama had been eagerly anticipating the fly-fishing trip, so much so that his Secret Service detail gave him his own personalized fishing rod. The president also has his own personal fly-fishing adviser: Jim Messina, Obama’s deputy chief of staff, is a Montana native.

New rod or not, Obama came up empty-handed, though his press secretary, Robert Gibbs, also a first-time fly fisherman, did land a fish.

“Look, he was dying to come here and go fishing,” Gibbs told reporters later. “Literally, we — every time we’d been to Montana — the primary, the general election, every time we went he said, ‘I’m going to come back here and learn how to fly fish.’ He was dying to do that, and finally got a chance to do that.” But, Gibbs added, the president “was a bit frustrated he didn’t get to hold one of the fish.”