Allie Kieffer, a former Arizona State runner who has elevated to one of the nation's top marathoners, was the women's half marathon winner in 1:13:34.
She also has been training in Flagstaff with coach Brad Hudson and will remain in the state for a while longer to continue preparing for the London Marathon on April 28.
"Adrienne Herzog (Barry) was kind of leading my group," Kieffer said. "Then I clipped her heels a couple of times, which is when you're going to slow. I wanted to pull back because I didn't really know what I was capable of, but I felt a lot better once I picked up the pace a little bit just before six miles.
"I wanted a hard long effort because that's really hard for me in practice. So I didn't taper for this race, I just came down to get in a good workout," off a 105-mile training week, she said.
Kieffer, 31, was seventh at the 2018 New York City Marathon after finishing fifth in 2017.
Like Dandena, she is qualified for the next U.S. Olympic Marathon Trials, Feb. 29, 2020, in Atlanta.
Cook falls just short of record third marathon title
Roosevelt Cook had a chance to become the first three-time RnR Arizona men's marathon champion but fell just short of defending his 2018 title.
Chris Mocko, 32, of Boulder, Colo., pulled away over the final 10K in the 26.2-mile journey through Phoenix and Scottsdale to Tempe, winning in a personal record 2:21:02.
Cook, 39, was runner-up in 2:25:28, nine seconds ahead of Kevin Horchler.
"I switched to trail running three years ago," Mocko. "I just qualified for Western States (100-mile, June 29-30) two weeks ago so this week was my first week of marathon training. I'm coming off 130 miles this week so I did not expect this today. I'm not complaining.
"It's a great race, and I'm so grateful the weather was nice. It seemed like there was more downhills than uphills, that's a good way to run."
Cook had his eighth podium (top 3) finish in nine RnR Arizona appearances, running six minutes faster than in 2018. He's had the most sustained success in Arizona since the late James Bungei won a string of high-profile 10K races in the late 1990s.
"This course is fast and he (Mocko) is an ultra marathoner," Cook said. "When you come from altitude, it's going to push you. I was trying to go fast too, but I couldn't get the rhythm I wanted early in the race to establish yourself. I wasn't out of energy, but my legs started cramping. No bonking (like in 2013). This time it was cramps and change of speed. I just maintained and got through them.
"I'm at the very top of my limit almost all the time. I can do it (break his PR of 2:23:22), but it has to be perfect position for me. I train by myself and it's different in a race holding that pace. Every time I come here, I come to represent and do my best."
The women's marathon winner was Maria Lindberg, 36, of Elmhurst, Ill., in 2:52:23. She has a four-minute edge over runner-up Jessica Culver (2:56:25).
"I'm happy with the win," Lindeberg said. "It's been five years since I've run a marathon so I was just getting back out here and seeing where I was at. I tend to run between kids. I had my third one a year ago so it took me awhile to get back it. Under three hours was my main goal."
Race officials said entrants for all races exceeded 16,000, including Arizona Sen. Kyrsten Sinema, who finished the half marathon in 1:49.
Humana Rock 'n' Roll Arizona
Marathon
Men
1. Chris Mocko, Boulder, Colo., 2:21:02
2. Roosevelt Cook, Oak Hills, Calif., 2:25:28
3. Kevin Horchler, La Mirada, Calif., 2:25:37
4. James Miles, Hawthorne, Calif., 2:33:38
5. Ramon Becerra, Mexico, 2:34:38
6. Tom Clarke, Anthem, 2:35:43
7. Kevin Cave, 2:41:11
8. Paul Lefrancois, Santa Fe, N.M., 2:43:11
9. Nick Coury, Scottsdale, 2:43:30
10. Thomas Lentz, Cincinnati, Ohio, 2:46:31
Women
1. Maria Lindberg, Elmhurst, Ill., 2:52:23
2. Jessica Culver, Tucson, 2:56:25
3. Stephanie Hankins, Louisville, Ky., 2:59:35
4. Molly Culver, St. Louis, 3:05:30
5. Monica Reyes, Mexico, 3:06:09
6. Carolina Sekaquaptewa, Tempe, 3:10:18
7. Alysha Krall, Gillette, Wyo., 3:12:41
8. Kristina Ballard, Lakewood, Colo., 3:16:04
9. Amanda Medoro, Albuquerque, N.M., 3:17:34
10. Emily Toia, Phoenix, 3:20:23
Half marathon
Men
1. Daniel Mesfun, Eritrea/Flagstaff, 1:01:12
2. Kiya Dandena, Flagstaff, 1:05:41
3. Saidi Makula, Flagstaff, 1:05:43
4. Scott Bauhs, San Luis Obispo, Calif., 1:06:28
5. Henry Sterling, 1:06:30
6. Ian Carter, 1:07:05
7. Japhaet Kipkoech, 1:07:33
8. Will Baldwin, 1:07:43
9. Rhys Park, Flagstaff, 1:09:01
10. Brandon Southall, Peoria, 1:11:20
Women
1. Allie Kieffer, Scottsdale, 1:13:35
2. Dylan Hassett, Providence, R.I., 1:15:15
3. Adrienne Barry, Englewood, Colo., 1:15:22
4. Anne Marie Kirkpatrick, Fort Collins, Colo., 1:15:36
5. Megan Lacy, Boise, Idaho, 1:16:46
6. Theresa Hailey, Portland, Ore., 1:17:24
7. Mariel Mendoza, 1:18:26
8. Kristen Rohde, Portland, Ore., 1:18:40
9. Lindy Jones, Colorado Springs, Colo., 1:18:51
10. Maggie Shearer, Newbury Park, Calif., 1:19:40
10K
Men
1. Harry Mulenga, 31:00
2. Alvin Begay, 33:10
3. Jason Lentzke, 34:16
4. Sverre Rosen, 35:35
5. Justin Pattee, 35:46
6. Christopher Keil, 36:59
7. Sean McNeil, 37:54
8. Filip Belik, 39:13
9. Lucas Moskovitz, 39:20
10. Tony Delogne, 39:32
Women
1. Lauren Reasoner, 38:13
2. Maeluen Gruman, 39:35
3. Kathryn Durrell, 39:52
4. Sara Nazemi, 41:54
5. Shokofeh Motlagh, 42:26
6. Hallidie Phillips, 42:44
7. Katy Clausen, 42:48
8. Nicole Schenk, 44:59
9. Dana Ioost, 45:42
10. Mandi Nilsen, 45:57