react-router-google-analytics.js

import React from 'react';
import { render } from 'react-dom';
import { Router } from 'react-router';
import createBrowserHistory from 'history/lib/createBrowserHistory';

import routes from './routes.js';

const history = createBrowserHistory();

// Setup google analytics tracking for react router transtions
history.listen(location => {
  window.ga('set', 'page', location.pathname);
  window.ga('send', 'pageview');
});

render(
  <Router routes={routes} history={history} />,
  document.getElementById('root')
);

An example using React Router 1.x with Google Analytics

Note that for this to work Google Analytics must already be loaded and present at window.ga.