The walk around Bear Lake would be pretty stroller friendly. Mostly asphalt, If IRRC.
Same with Sprague Lake on the drive up to Bear Lake. Nice little fishing lake with an easy trail around it, plus it has nice picnic areas.
Both of those lakes have spectacular views of the mountains!
and I should clarify we have an "off road" stroller so it can handle some rough terrain. I'd say if you would trail run it, we'd stroller it.