( Updated with additional Metro info Friday ): WASHINGTON, DC — A massive rally is about to descend on Washington, D.C. this weekend as hundreds of thousands are expected to attend the "March For Our Lives" on Saturday, March 24. The rally is taking place in response to the slaying of 17 students at a Florida high school last month by a student armed with an AR-15, and it will include calls for increased gun control nationwide.

Since the Parkland shooting, a handful of MCPS students formed a group called " Montgomery County Students For Gun Control ." The group organized the local walk out and is promoting the March For Our Lives.

Montgomery County students are planning to attend the March, about a week-and-a-half after thousands walked out of their classrooms for the "ENOUGH National School Walkout" on Wednesday, March 14.

MCPS students will wear orange to school on Friday in support of the fight for gun control and in preparation for the March.

It's estimated that 2,500 MCPS students walked out from: Montgomery Blair High School, Richard Montgomery High School, Springbrook High School, Winston Churchhill High School, Blake High School, Walter Johnson High School, Northwood High School, Quince Orchard High School, Clarksburg High School, Bethesda-Chevy Chase High School, Rockville High School, Gaithersburg High School and Albert Einstein High School.

"I'm delighted that high school students are taking the lead because of the anxiety and fear they're experiencing in their every day lives," Montgomery County Councilmember George Leventhal told Montgomery Community Media. "... I hope that in this moment, the young will lead us to a solution and a consensus."

Matt Post, the student member of the Montgomery County school board, will give a speech at Saturday's march. He will be joined by Montgomery County Students For Gun Control leaders Brenna Levitan, Nate Tinbite and Michael Solomon.

March For Our Lives gained attention Tuesday as word spread nationwide about a Maryland school shooting about 65 miles from Washington, D.C. A student opened fire at Great Mills High School Tuesday morning in St. Mary's County, Maryland. Two students suffered gunshots wounds, the shooter exchanged gunshots with a school resource officer, and the gunman was pronounced dead at an area hospital.

Here's everything you need to know about Saturday's march:

While it is called a march, it is likely to be more of a rally. It was spawned after the massacre of 17 students at Marjory Stoneman Douglas High School in Parkland, Fla., on Feb. 14. Police accused Nicholas Cruz, a former student, of conducting the rampage while armed with an AR-15.

What is the "March For Our Lives"?

The shooting caused a huge eruption of outrage across the country, and resulted in school walkouts both shortly after the event and on March 14, exactly one month after the event. The March For Our Lives rally is the culmination of the largely student-led movements.

"It is important to remember why we must fight so hard to get stricter gun control legislation in this country," Brenna Levitan, a senior at Montgomery Blair High School who helped form Montgomery County Students For Gun Control, told Buzzfeed News. "It is important to remember who we are fighting for, because it is not just ourselves and our peers, but also for all the students, friends, and loved ones who are no longer able to fight for themselves."



The will be a far more partisan affair. The walkouts were intended primarily to mourn the victims at Parkland, while the rally will be focused on demanding more gun control.

Gun rights advocates, especially the National Rifle Association, are resisting efforts to increase gun control measures, including raising the age limit to buy weapons or banning the AR-15 altogether. This event is expected to be a major rallying cry in favor of greater gun restrictions and against the influence of the NRA in politics in general.

Who is organizing it?



Student organizers are planning the March, in collaboration with nonprofit Everytown for Gun Safety and with the support of wealthy donors. Cameron Kasky, a junior at Marjory Stoneman Douglas High, announced the March -- along with his classmates -- back on Feb. 18. It quickly snowballed.

The March has attracted financial support from celebrities, including Amal and George Clooney, Jeffrey Katzenberg, Oprah Winfrey, and Steven Spielberg, who are the most significant donors ($500,000 each). Many other celebrities have offered support as well.



Ariana Grande, Miley Cyrus, Jennifer Hudson, and Demi Lovato are expected to join the marchers in D.C.

Meet the kids behind @moco4guncontrol. These student activists organized all 25 high schools in Montgomery County, MD to rally at the Capitol in response to Parkland. They are in high school. These kids are our future. Young people are changing the pic.twitter.com/Zz5kRbf38R

— Brenna Parker (@BrennaParker1) March 9, 2018

>> See Related: 'We're Afraid To Go To School' Montgomery Students Say At Capitol

When and where will it take place?



The march is scheduled to start at noon ET on Saturday, March 24.

The march route will run along Pennsylvania Avenue in downtown D.C., from 3rd Street (near the front of the U.S. Capitol) to 12th Street (a few blocks from the White House and near the entrance of Trump International Hotel).

What transportation options are available to get to the rally?



Getting to the rally will not be easy no matter what transportation option you choose, if as many people attend as the NPS believes. The Women's March on Washington made driving anywhere near the National Mall impossible, let alone finding any parking. And Metro trains were totally jammed with people, resulting in long waits just to get on an inbound train.

Your best bet is to arrive early -- very early, many hours before the event -- to get a Metro train into the city. Otherwise, be prepared to take a taxi or Uber to some place many blocks away and walk.

If you're in Montgomery County, Rep. Jamie Raskin (MD-08) is holding a pre-march rally at the Silver Spring Civic Building at 9 a.m. Saturday.

"As with the Women's March last year, I'm inviting all 8th District friends and families—from Montgomery, Frederick, and Carroll Counties and beyond—to assemble at the Silver Spring Civic Building at 9:00 AM, for a pre-March Rally with soul-lifting music, high school a capella groups, and a dazzling and growing coalition of local activist groups, including Moms Demand Action, MoCo Women, the Women's Democratic Club, DotheMostGood, and Our Revolution, which graciously offered us the space which they had reserved for a conference they're rescheduling," Raskin said in a Facebook post.

>> Please email events@jamieraskin.com if you have questions.

The 6th District congressional candidate David Trone is also providing free bus transportation, breakfast on the bus ride over and transportation back to Rockville after the March.

Buses will load and depart at 9 a.m. from the Shady Grove Metro Stop at 15903 Somerville Dr. They will make return trips starting at 3 p.m. until 4 p.m. from the Bureau of Engraving and Printing at 301 14th St SW., D.C.

Maryland Attorney General Brian Frosh will cycle ten miles to the mall from Bethesda and is inviting residents to join him, according to Bethesda Magazine. Frosh will meet other riders at Little Falls Park at 6300 Little Falls Parkway and will leave at about 10:30 a.m.

Metro has developed service plans to support extremely large crowds from the March and tourists coming to see the cherry blossoms. Here are Saturday's service changes:

Metro will run rush-hour service levels throughout the day to accommodate expected crowds. The rail system will open at 7 a.m. Customers are encouraged to travel as early in the day as possible.

Trains will depart end-of-line stations every 8 minutes, and additional Red Line trains will run between Grosvenor and Silver Spring. In Downtown DC, trains will arrive every 2-4 minutes.

Yellow Line trains from Huntington will operate to Mt Vernon Sq or Greenbelt.

Metrobus service will be impacted around Pennsylvania Avenue. Some routes will detour or not operate the full route. Click here for service changes

Metro is advising customers:

Plan ahead. Every Metro rider (age 5 and up) needs his or her own SmarTrip card. To avoid long lines on March 24, purchase your SmarTrip card in advance from any Metrorail station, CVS Pharmacy or Giant Food stores. On-line orders after Friday, March 9 will still be accepted but may not be received prior to the event due to fulfillment and shipping times.

There is a Metro station near the March location on each of the system's rail lines, so can get to the event by taking just one train. Plan your trip so that you do not have to transfer between rail lines.

Expect large crowds. The March, combined with Cherry Blossom visitors, could result in one of Metro's highest ridership days. Plan for the possibility of lines and intermittent delays due to crowds.

Travel light. To make room for everyone, bicycles, large coolers and other oversized items will not be permitted on Metrorail on March 24.

Federal Triangle Station will be closed. Use Metro Center Station instead.

Selected station entrances may be designated "entry only" or "exit only" at various times to help speed your trip.

Stay connected. Follow @wmata and @metrorailinfo for updated information on Metro service before, during and after the March.

How many are expected to attend?



The National Park Service expects 500,000 to attend the rally in D.C. That would place it about on par with the Women's March on Washington that took place the day after President Trump's inauguration in January 2016.

Where are other rallies taking place?



Hundreds of rallies, too numerous to list here, will be taking place across the United States in conjunction with the event so that people who can't make it to D.C. can express their support for tighter gun control measures. Just about every major city is likely to see a demonstration of some kind, as well as most mid-range cities.

According to the March For Our Lives website, there will be 819 events worldwide. You can visit their website to search for one near you.

Where can I find more information?



The March For Our Lives website is here. You can also download the March For Our Lives app for free, which provides information like schedules and maps on your mobile phone.

Photos by Cameron Luttrell/Patch Editor